diff --git a/src/lib/audit.ts b/src/lib/audit.ts
index 9ccf3fc..df45ead 100644
--- a/src/lib/audit.ts
+++ b/src/lib/audit.ts
@@ -18,6 +18,19 @@ export type AuditAction =
   | 'request_gdpr_export'
   | 'send_gdpr_export';
 
+/**
+ * Common shape passed to service functions so they can stamp audit logs and
+ * propagate request context. Every authenticated route resolves these from
+ * the session + headers; services accept them rather than reaching into
+ * Next.js APIs themselves.
+ */
+export interface AuditMeta {
+  userId: string;
+  portId: string;
+  ipAddress: string;
+  userAgent: string;
+}
+
 export interface AuditLogParams {
   /** Null for system-generated events. */
   userId: string | null;
diff --git a/src/lib/services/berth-reservations.service.ts b/src/lib/services/berth-reservations.service.ts
index 1516ed0..6b26683 100644
--- a/src/lib/services/berth-reservations.service.ts
+++ b/src/lib/services/berth-reservations.service.ts
@@ -6,7 +6,7 @@ import { clients } from '@/lib/db/schema/clients';
 import { yachts } from '@/lib/db/schema/yachts';
 import { companyMemberships } from '@/lib/db/schema/companies';
 import { buildListQuery } from '@/lib/db/query-builder';
-import { createAuditLog } from '@/lib/audit';
+import { createAuditLog, type AuditMeta } from '@/lib/audit';
 import { ConflictError, NotFoundError, ValidationError } from '@/lib/errors';
 import { emitToRoom } from '@/lib/socket/server';
 import type { z } from 'zod';
@@ -22,13 +22,6 @@ type CreatePendingInput = z.input<typeof createPendingSchema>;
 
 export type { BerthReservation };
 
-interface AuditMeta {
-  userId: string;
-  portId: string;
-  ipAddress: string;
-  userAgent: string;
-}
-
 // ─── Helpers ─────────────────────────────────────────────────────────────────
 
 /**
diff --git a/src/lib/services/berth-rules-engine.ts b/src/lib/services/berth-rules-engine.ts
index d9fa1ae..69fd972 100644
--- a/src/lib/services/berth-rules-engine.ts
+++ b/src/lib/services/berth-rules-engine.ts
@@ -4,7 +4,7 @@ import { db } from '@/lib/db';
 import { interests } from '@/lib/db/schema/interests';
 import { berths } from '@/lib/db/schema/berths';
 import { systemSettings } from '@/lib/db/schema/system';
-import { createAuditLog } from '@/lib/audit';
+import { createAuditLog, type AuditMeta } from '@/lib/audit';
 import { emitToRoom } from '@/lib/socket/server';
 
 // ─── Types ────────────────────────────────────────────────────────────────────
@@ -31,13 +31,6 @@ interface RuleConfig {
   targetStatus: string;
 }
 
-interface AuditMeta {
-  userId: string;
-  portId: string;
-  ipAddress: string;
-  userAgent: string;
-}
-
 // ─── Defaults ────────────────────────────────────────────────────────────────
 
 const DEFAULT_RULES: Record<BerthRuleTrigger, RuleConfig> = {
@@ -52,14 +45,9 @@ const DEFAULT_RULES: Record<BerthRuleTrigger, RuleConfig> = {
 
 // ─── Config ───────────────────────────────────────────────────────────────────
 
-async function getRulesConfig(
-  portId: string,
-): Promise<Record<BerthRuleTrigger, RuleConfig>> {
+async function getRulesConfig(portId: string): Promise<Record<BerthRuleTrigger, RuleConfig>> {
   const setting = await db.query.systemSettings.findFirst({
-    where: and(
-      eq(systemSettings.key, 'berth_rules'),
-      eq(systemSettings.portId, portId),
-    ),
+    where: and(eq(systemSettings.key, 'berth_rules'), eq(systemSettings.portId, portId)),
   });
 
   if (!setting?.value) {
diff --git a/src/lib/services/berths.service.ts b/src/lib/services/berths.service.ts
index d21e01d..9015d50 100644
--- a/src/lib/services/berths.service.ts
+++ b/src/lib/services/berths.service.ts
@@ -3,11 +3,12 @@ import { and, eq, gte, lte, inArray } from 'drizzle-orm';
 import { db } from '@/lib/db';
 import { berths, berthTags, berthWaitingList, berthMaintenanceLog } from '@/lib/db/schema/berths';
 import { tags } from '@/lib/db/schema/system';
-import { createAuditLog } from '@/lib/audit';
+import { createAuditLog, type AuditMeta } from '@/lib/audit';
 import { diffEntity } from '@/lib/entity-diff';
 import { NotFoundError } from '@/lib/errors';
 import { buildListQuery } from '@/lib/db/query-builder';
 import { emitToRoom } from '@/lib/socket/server';
+import { setEntityTags } from '@/lib/services/entity-tags.helper';
 import { ConflictError } from '@/lib/errors';
 import type {
   CreateBerthInput,
@@ -18,13 +19,6 @@ import type {
   UpdateWaitingListInput,
 } from '@/lib/validators/berths';
 
-interface AuditMeta {
-  userId: string;
-  portId: string;
-  ipAddress: string;
-  userAgent: string;
-}
-
 // ─── List ─────────────────────────────────────────────────────────────────────
 
 export async function listBerths(portId: string, query: ListBerthsQuery) {
@@ -300,30 +294,18 @@ export async function setBerthTags(id: string, portId: string, tagIds: string[],
   });
   if (!existing) throw new NotFoundError('Berth');
 
-  // Delete existing tags then insert new ones
-  await db.delete(berthTags).where(eq(berthTags.berthId, id));
-
-  if (tagIds.length > 0) {
-    await db.insert(berthTags).values(tagIds.map((tagId) => ({ berthId: id, tagId })));
-  }
-
-  void createAuditLog({
-    userId: meta.userId,
-    portId,
-    action: 'update',
-    entityType: 'berth',
+  const result = await setEntityTags({
+    joinTable: berthTags,
+    entityColumn: berthTags.berthId,
+    tagColumn: berthTags.tagId,
     entityId: id,
-    metadata: { type: 'tags_updated', tagIds },
-    ipAddress: meta.ipAddress,
-    userAgent: meta.userAgent,
+    portId,
+    tagIds,
+    meta,
+    entityType: 'berth',
   });
 
-  emitToRoom(`port:${portId}`, 'berth:updated', {
-    berthId: id,
-    changedFields: ['tags'],
-  });
-
-  return { berthId: id, tagIds };
+  return { berthId: result.entityId, tagIds: result.tagIds };
 }
 
 // ─── Add Maintenance Log ──────────────────────────────────────────────────────
diff --git a/src/lib/services/clients.service.ts b/src/lib/services/clients.service.ts
index a40c02d..fb9b57f 100644
--- a/src/lib/services/clients.service.ts
+++ b/src/lib/services/clients.service.ts
@@ -12,9 +12,10 @@ import { companies, companyMemberships } from '@/lib/db/schema/companies';
 import { yachts } from '@/lib/db/schema/yachts';
 import { berthReservations } from '@/lib/db/schema/reservations';
 import { tags } from '@/lib/db/schema/system';
-import { createAuditLog } from '@/lib/audit';
+import { createAuditLog, type AuditMeta } from '@/lib/audit';
 import { NotFoundError } from '@/lib/errors';
 import { isPortalEnabledForPort } from '@/lib/services/portal-auth.service';
+import { setEntityTags } from '@/lib/services/entity-tags.helper';
 import { emitToRoom } from '@/lib/socket/server';
 import { buildListQuery } from '@/lib/db/query-builder';
 import { diffEntity } from '@/lib/entity-diff';
@@ -27,13 +28,6 @@ import type {
 
 // ─── Types ────────────────────────────────────────────────────────────────────
 
-interface AuditMeta {
-  userId: string;
-  portId: string;
-  ipAddress: string;
-  userAgent: string;
-}
-
 // ─── List ─────────────────────────────────────────────────────────────────────
 
 export async function listClients(portId: string, query: ListClientsInput) {
@@ -637,24 +631,16 @@ export async function setClientTags(
   });
   if (!client || client.portId !== portId) throw new NotFoundError('Client');
 
-  await db.delete(clientTags).where(eq(clientTags.clientId, clientId));
-
-  if (tagIds.length > 0) {
-    await db.insert(clientTags).values(tagIds.map((tagId) => ({ clientId, tagId })));
-  }
-
-  void createAuditLog({
-    userId: meta.userId,
-    portId,
-    action: 'update',
-    entityType: 'client',
+  await setEntityTags({
+    joinTable: clientTags,
+    entityColumn: clientTags.clientId,
+    tagColumn: clientTags.tagId,
     entityId: clientId,
-    newValue: { tagIds },
-    ipAddress: meta.ipAddress,
-    userAgent: meta.userAgent,
+    portId,
+    tagIds,
+    meta,
+    entityType: 'client',
   });
-
-  emitToRoom(`port:${portId}`, 'client:updated', { clientId, changedFields: ['tags'] });
 }
 
 // ─── Relationships ────────────────────────────────────────────────────────────
diff --git a/src/lib/services/companies.service.ts b/src/lib/services/companies.service.ts
index dbd1ea6..2c74d5a 100644
--- a/src/lib/services/companies.service.ts
+++ b/src/lib/services/companies.service.ts
@@ -10,9 +10,10 @@ import type { Company } from '@/lib/db/schema/companies';
 import { yachts } from '@/lib/db/schema/yachts';
 import { withTransaction } from '@/lib/db/utils';
 import { buildListQuery } from '@/lib/db/query-builder';
-import { createAuditLog } from '@/lib/audit';
+import { createAuditLog, type AuditMeta } from '@/lib/audit';
 import { NotFoundError, ConflictError } from '@/lib/errors';
 import { emitToRoom } from '@/lib/socket/server';
+import { setEntityTags } from '@/lib/services/entity-tags.helper';
 import { diffEntity } from '@/lib/entity-diff';
 import type { z } from 'zod';
 import type {
@@ -23,13 +24,6 @@ import type {
 
 type CreateCompanyInput = z.input<typeof createCompanySchema>;
 
-interface AuditMeta {
-  userId: string;
-  portId: string;
-  ipAddress: string;
-  userAgent: string;
-}
-
 export type { Company };
 
 // ─── Helpers ─────────────────────────────────────────────────────────────────
@@ -364,24 +358,16 @@ export async function setCompanyTags(
   const company = await db.query.companies.findFirst({ where: eq(companies.id, companyId) });
   if (!company || company.portId !== portId) throw new NotFoundError('Company');
 
-  await db.delete(companyTags).where(eq(companyTags.companyId, companyId));
-
-  if (tagIds.length > 0) {
-    await db.insert(companyTags).values(tagIds.map((tagId) => ({ companyId, tagId })));
-  }
-
-  void createAuditLog({
-    userId: meta.userId,
-    portId,
-    action: 'update',
-    entityType: 'company',
+  await setEntityTags({
+    joinTable: companyTags,
+    entityColumn: companyTags.companyId,
+    tagColumn: companyTags.tagId,
     entityId: companyId,
-    newValue: { tagIds },
-    ipAddress: meta.ipAddress,
-    userAgent: meta.userAgent,
+    portId,
+    tagIds,
+    meta,
+    entityType: 'company',
   });
-
-  emitToRoom(`port:${portId}`, 'company:updated', { companyId, changedFields: ['tags'] });
 }
 
 // ─── Addresses ────────────────────────────────────────────────────────────────
diff --git a/src/lib/services/company-memberships.service.ts b/src/lib/services/company-memberships.service.ts
index dc9a3e8..dda798f 100644
--- a/src/lib/services/company-memberships.service.ts
+++ b/src/lib/services/company-memberships.service.ts
@@ -4,7 +4,7 @@ import { companies, companyMemberships } from '@/lib/db/schema/companies';
 import type { CompanyMembership } from '@/lib/db/schema/companies';
 import { clients } from '@/lib/db/schema/clients';
 import { withTransaction } from '@/lib/db/utils';
-import { createAuditLog } from '@/lib/audit';
+import { createAuditLog, type AuditMeta } from '@/lib/audit';
 import { NotFoundError, ConflictError, ValidationError } from '@/lib/errors';
 import { emitToRoom } from '@/lib/socket/server';
 import { diffEntity } from '@/lib/entity-diff';
@@ -14,13 +14,6 @@ import type {
   EndMembershipInput,
 } from '@/lib/validators/company-memberships';
 
-interface AuditMeta {
-  userId: string;
-  portId: string;
-  ipAddress: string;
-  userAgent: string;
-}
-
 export type { CompanyMembership };
 
 // ─── Helpers ─────────────────────────────────────────────────────────────────
diff --git a/src/lib/services/crm-invite.service.ts b/src/lib/services/crm-invite.service.ts
index 86203d4..c13bc20 100644
--- a/src/lib/services/crm-invite.service.ts
+++ b/src/lib/services/crm-invite.service.ts
@@ -2,7 +2,7 @@ import { and, desc, eq, gt, isNull } from 'drizzle-orm';
 import postgres from 'postgres';
 
 import { auth } from '@/lib/auth';
-import { createAuditLog } from '@/lib/audit';
+import { createAuditLog, type AuditMeta } from '@/lib/audit';
 import { db } from '@/lib/db';
 import { crmUserInvites } from '@/lib/db/schema/crm-invites';
 import { userProfiles } from '@/lib/db/schema/users';
@@ -12,13 +12,6 @@ import { crmInviteEmail } from '@/lib/email/templates/crm-invite';
 import { ConflictError, NotFoundError, ValidationError } from '@/lib/errors';
 import { hashToken, mintToken } from '@/lib/portal/passwords';
 
-interface AuditMeta {
-  userId: string;
-  portId: string;
-  ipAddress: string;
-  userAgent: string;
-}
-
 const INVITE_TTL_HOURS = 72;
 const MIN_PASSWORD_LENGTH = 9;
 
diff --git a/src/lib/services/custom-fields.service.ts b/src/lib/services/custom-fields.service.ts
index a9d1d6b..605c31d 100644
--- a/src/lib/services/custom-fields.service.ts
+++ b/src/lib/services/custom-fields.service.ts
@@ -2,20 +2,13 @@ import { and, eq, count } from 'drizzle-orm';
 
 import { db } from '@/lib/db';
 import { customFieldDefinitions, customFieldValues } from '@/lib/db/schema/system';
-import { createAuditLog } from '@/lib/audit';
+import { createAuditLog, type AuditMeta } from '@/lib/audit';
 import { NotFoundError, ValidationError, ConflictError } from '@/lib/errors';
 import type { CreateFieldInput, UpdateFieldInput } from '@/lib/validators/custom-fields';
 import type { CustomFieldDefinition } from '@/lib/db/schema/system';
 
 // ─── Types ────────────────────────────────────────────────────────────────────
 
-interface AuditMeta {
-  userId: string;
-  portId: string;
-  ipAddress: string;
-  userAgent: string;
-}
-
 // ─── Value Validation ─────────────────────────────────────────────────────────
 
 function validateCustomFieldValue(
@@ -35,16 +28,12 @@ function validateCustomFieldValue(
     case 'number':
       return typeof value !== 'number' || isNaN(value) ? 'Must be a number' : null;
     case 'date':
-      return typeof value !== 'string' || isNaN(Date.parse(value))
-        ? 'Must be a valid date'
-        : null;
+      return typeof value !== 'string' || isNaN(Date.parse(value)) ? 'Must be a valid date' : null;
     case 'boolean':
       return typeof value !== 'boolean' ? 'Must be true or false' : null;
     case 'select': {
       const options = (definition.selectOptions as string[] | null) ?? [];
-      return !options.includes(value as string)
-        ? `Must be one of: ${options.join(', ')}`
-        : null;
+      return !options.includes(value as string) ? `Must be one of: ${options.join(', ')}` : null;
     }
     default:
       return 'Unknown field type';
@@ -134,10 +123,7 @@ export async function updateDefinition(
   }
 
   const existing = await db.query.customFieldDefinitions.findFirst({
-    where: and(
-      eq(customFieldDefinitions.id, fieldId),
-      eq(customFieldDefinitions.portId, portId),
-    ),
+    where: and(eq(customFieldDefinitions.id, fieldId), eq(customFieldDefinitions.portId, portId)),
   });
   if (!existing) {
     throw new NotFoundError('Custom field definition');
@@ -189,10 +175,7 @@ export async function deleteDefinition(
   meta: AuditMeta,
 ) {
   const existing = await db.query.customFieldDefinitions.findFirst({
-    where: and(
-      eq(customFieldDefinitions.id, fieldId),
-      eq(customFieldDefinitions.portId, portId),
-    ),
+    where: and(eq(customFieldDefinitions.id, fieldId), eq(customFieldDefinitions.portId, portId)),
   });
   if (!existing) {
     throw new NotFoundError('Custom field definition');
@@ -206,9 +189,7 @@ export async function deleteDefinition(
   const valueCount = countResult[0]?.count ?? 0;
 
   // Delete definition — CASCADE handles values
-  await db
-    .delete(customFieldDefinitions)
-    .where(eq(customFieldDefinitions.id, fieldId));
+  await db.delete(customFieldDefinitions).where(eq(customFieldDefinitions.id, fieldId));
 
   void createAuditLog({
     userId,
diff --git a/src/lib/services/document-templates.service.ts b/src/lib/services/document-templates.service.ts
index edeb883..658c9f5 100644
--- a/src/lib/services/document-templates.service.ts
+++ b/src/lib/services/document-templates.service.ts
@@ -15,7 +15,7 @@ import { and, eq, desc } from 'drizzle-orm';
 import { db } from '@/lib/db';
 import { documentTemplates } from '@/lib/db/schema/documents';
 import { auditLogs } from '@/lib/db/schema/system';
-import { createAuditLog } from '@/lib/audit';
+import { createAuditLog, type AuditMeta } from '@/lib/audit';
 import { NotFoundError, ValidationError } from '@/lib/errors';
 import { validateTipTapDocument } from '@/lib/pdf/tiptap-to-pdfme';
 import type {
@@ -26,13 +26,6 @@ import type {
 
 // ─── Types ────────────────────────────────────────────────────────────────────
 
-export interface AuditMeta {
-  userId: string;
-  portId: string;
-  ipAddress: string;
-  userAgent: string;
-}
-
 /**
  * A version entry reconstructed from audit_log records.
  */
diff --git a/src/lib/services/document-templates.ts b/src/lib/services/document-templates.ts
index 3b18a9a..bd6087f 100644
--- a/src/lib/services/document-templates.ts
+++ b/src/lib/services/document-templates.ts
@@ -9,7 +9,7 @@ import { berths } from '@/lib/db/schema/berths';
 import { ports } from '@/lib/db/schema/ports';
 import { yachts } from '@/lib/db/schema/yachts';
 import { buildListQuery } from '@/lib/db/query-builder';
-import { createAuditLog } from '@/lib/audit';
+import { createAuditLog, type AuditMeta } from '@/lib/audit';
 import { diffEntity } from '@/lib/entity-diff';
 import { NotFoundError, ValidationError } from '@/lib/errors';
 import { emitToRoom } from '@/lib/socket/server';
@@ -38,13 +38,6 @@ import type {
 
 // ─── Types ────────────────────────────────────────────────────────────────────
 
-interface AuditMeta {
-  userId: string;
-  portId: string;
-  ipAddress: string;
-  userAgent: string;
-}
-
 // ─── Merge Field Definitions ──────────────────────────────────────────────────
 
 export function getMergeFields(): MergeFieldCatalog {
diff --git a/src/lib/services/documents.service.ts b/src/lib/services/documents.service.ts
index f58ca22..c0780d0 100644
--- a/src/lib/services/documents.service.ts
+++ b/src/lib/services/documents.service.ts
@@ -12,7 +12,7 @@ import { interests } from '@/lib/db/schema/interests';
 import { clients } from '@/lib/db/schema/clients';
 import { ports } from '@/lib/db/schema/ports';
 import { buildListQuery } from '@/lib/db/query-builder';
-import { createAuditLog } from '@/lib/audit';
+import { createAuditLog, type AuditMeta } from '@/lib/audit';
 import { diffEntity } from '@/lib/entity-diff';
 import { NotFoundError, ValidationError, ConflictError } from '@/lib/errors';
 import { emitToRoom } from '@/lib/socket/server';
@@ -34,13 +34,6 @@ import type {
 
 // ─── Types ────────────────────────────────────────────────────────────────────
 
-interface AuditMeta {
-  userId: string;
-  portId: string;
-  ipAddress: string;
-  userAgent: string;
-}
-
 // ─── List ─────────────────────────────────────────────────────────────────────
 
 import { documentWatchers as documentWatchersTable } from '@/lib/db/schema/documents';
diff --git a/src/lib/services/email-accounts.service.ts b/src/lib/services/email-accounts.service.ts
index d1cf2f6..349d880 100644
--- a/src/lib/services/email-accounts.service.ts
+++ b/src/lib/services/email-accounts.service.ts
@@ -3,26 +3,17 @@ import { and, eq } from 'drizzle-orm';
 import { db } from '@/lib/db';
 import { emailAccounts } from '@/lib/db/schema/email';
 import { encrypt, decrypt } from '@/lib/utils/encryption';
-import { createAuditLog } from '@/lib/audit';
+import { createAuditLog, type AuditMeta } from '@/lib/audit';
 import { NotFoundError, ForbiddenError } from '@/lib/errors';
 import type { ConnectAccountInput, ToggleAccountInput } from '@/lib/validators/email';
 
 // ─── Types ────────────────────────────────────────────────────────────────────
 
-interface AuditMeta {
-  userId: string;
-  portId: string;
-  ipAddress: string;
-  userAgent: string;
-}
-
 type AccountWithoutCredentials = Omit<typeof emailAccounts.$inferSelect, 'credentialsEnc'>;
 
 // ─── Helpers ──────────────────────────────────────────────────────────────────
 
-function stripCredentials(
-  account: typeof emailAccounts.$inferSelect,
-): AccountWithoutCredentials {
+function stripCredentials(account: typeof emailAccounts.$inferSelect): AccountWithoutCredentials {
   // eslint-disable-next-line @typescript-eslint/no-unused-vars
   const { credentialsEnc: _, ...safe } = account;
   return safe;
diff --git a/src/lib/services/email-compose.service.ts b/src/lib/services/email-compose.service.ts
index 606a435..c163c06 100644
--- a/src/lib/services/email-compose.service.ts
+++ b/src/lib/services/email-compose.service.ts
@@ -4,7 +4,7 @@ import { and, eq, sql } from 'drizzle-orm';
 import { db } from '@/lib/db';
 import { emailAccounts, emailMessages, emailThreads } from '@/lib/db/schema/email';
 import { documents, documentEvents, files } from '@/lib/db/schema/documents';
-import { createAuditLog } from '@/lib/audit';
+import { createAuditLog, type AuditMeta } from '@/lib/audit';
 import { NotFoundError, ForbiddenError } from '@/lib/errors';
 import { getDecryptedCredentials } from '@/lib/services/email-accounts.service';
 import { getPortEmailConfig } from '@/lib/services/port-config';
@@ -13,13 +13,6 @@ import type { ComposeEmailInput } from '@/lib/validators/email';
 
 // ─── Types ────────────────────────────────────────────────────────────────────
 
-interface AuditMeta {
-  userId: string;
-  portId: string;
-  ipAddress: string;
-  userAgent: string;
-}
-
 // ─── Helpers ──────────────────────────────────────────────────────────────────
 
 async function assertAttachmentsForPort(
diff --git a/src/lib/services/entity-tags.helper.ts b/src/lib/services/entity-tags.helper.ts
new file mode 100644
index 0000000..acf5279
--- /dev/null
+++ b/src/lib/services/entity-tags.helper.ts
@@ -0,0 +1,110 @@
+/**
+ * Wipe-and-rewrite tag-assignment helper, shared by every entity that has
+ * a many-to-many tag join table (`client_tags`, `yacht_tags`, …).
+ *
+ * The recipe is the same for every entity:
+ *   1. wipe the join rows for this entity
+ *   2. insert the new set
+ *   3. write an audit log
+ *   4. emit a socket event
+ *
+ * This helper performs the wipe+insert inside a single transaction so a
+ * partial failure can't leave the entity with zero tags, and standardizes
+ * the audit-log payload to `newValue: { tagIds }` across all entity types.
+ */
+
+import { eq, type Column } from 'drizzle-orm';
+import type { PgTable } from 'drizzle-orm/pg-core';
+
+import { withTransaction } from '@/lib/db/utils';
+import { createAuditLog, type AuditMeta } from '@/lib/audit';
+import { emitToRoom } from '@/lib/socket/server';
+
+interface SetEntityTagsArgs<TJoin extends PgTable> {
+  /** Join table — e.g. `clientTags`, `yachtTags`. */
+  joinTable: TJoin;
+  /**
+   * Column on the join table that points back at the parent entity (e.g.
+   * `clientTags.clientId`). Used both for the WHERE on delete and as the
+   * insert payload key.
+   */
+  entityColumn: Column;
+  /** Column on the join table that holds the tag ID (e.g. `clientTags.tagId`). */
+  tagColumn: Column;
+  /** Owning entity ID. */
+  entityId: string;
+  /** Tenant scope. */
+  portId: string;
+  /** Final desired set of tag IDs (replaces current set). */
+  tagIds: string[];
+  /** Audit log + socket fields. */
+  meta: AuditMeta;
+  /**
+   * Audit/socket entity discriminator. Drives both `entityType` on the
+   * audit row and the socket event name (`<entityType>:updated`).
+   */
+  entityType: 'client' | 'company' | 'yacht' | 'interest' | 'berth';
+}
+
+export async function setEntityTags<TJoin extends PgTable>(
+  args: SetEntityTagsArgs<TJoin>,
+): Promise<{ entityId: string; tagIds: string[] }> {
+  const { joinTable, entityColumn, tagColumn, entityId, portId, tagIds, meta, entityType } = args;
+
+  await withTransaction(async (tx) => {
+    await tx.delete(joinTable).where(eq(entityColumn, entityId));
+    if (tagIds.length > 0) {
+      await tx.insert(joinTable).values(
+        tagIds.map(
+          (tagId) =>
+            ({
+              [entityColumn.name]: entityId,
+              [tagColumn.name]: tagId,
+            }) as TJoin['$inferInsert'],
+        ),
+      );
+    }
+  });
+
+  void createAuditLog({
+    userId: meta.userId,
+    portId,
+    action: 'update',
+    entityType,
+    entityId,
+    newValue: { tagIds },
+    ipAddress: meta.ipAddress,
+    userAgent: meta.userAgent,
+  });
+
+  // Per-event payloads use entity-specific keys (e.g. `clientId` vs `yachtId`),
+  // so dispatch through a switch rather than a computed property to keep the
+  // ServerToClientEvents typing happy.
+  const room = `port:${portId}` as const;
+  const changedFields = ['tags'] as const;
+  switch (entityType) {
+    case 'client':
+      emitToRoom(room, 'client:updated', { clientId: entityId, changedFields: [...changedFields] });
+      break;
+    case 'company':
+      emitToRoom(room, 'company:updated', {
+        companyId: entityId,
+        changedFields: [...changedFields],
+      });
+      break;
+    case 'yacht':
+      emitToRoom(room, 'yacht:updated', { yachtId: entityId, changedFields: [...changedFields] });
+      break;
+    case 'interest':
+      emitToRoom(room, 'interest:updated', {
+        interestId: entityId,
+        changedFields: [...changedFields],
+      });
+      break;
+    case 'berth':
+      emitToRoom(room, 'berth:updated', { berthId: entityId, changedFields: [...changedFields] });
+      break;
+  }
+
+  return { entityId, tagIds };
+}
diff --git a/src/lib/services/expenses.ts b/src/lib/services/expenses.ts
index 95c92dd..20b82d3 100644
--- a/src/lib/services/expenses.ts
+++ b/src/lib/services/expenses.ts
@@ -4,7 +4,7 @@ import type { PgColumn } from 'drizzle-orm/pg-core';
 import { db } from '@/lib/db';
 import { expenses, invoices, invoiceExpenses } from '@/lib/db/schema/financial';
 import { buildListQuery } from '@/lib/db/query-builder';
-import { createAuditLog } from '@/lib/audit';
+import { createAuditLog, type AuditMeta } from '@/lib/audit';
 import { diffEntity } from '@/lib/entity-diff';
 import { softDelete, restore } from '@/lib/db/utils';
 import { NotFoundError, ConflictError } from '@/lib/errors';
@@ -19,14 +19,6 @@ import type {
 
 export type { ListExpensesInput };
 
-// AuditMeta type expected by service functions
-export interface ServiceAuditMeta {
-  userId: string;
-  portId: string;
-  ipAddress: string;
-  userAgent: string;
-}
-
 export async function listExpenses(portId: string, query: ListExpensesInput) {
   const filters = [];
 
@@ -79,11 +71,7 @@ export async function getExpenseById(id: string, portId: string) {
   return expense;
 }
 
-export async function createExpense(
-  portId: string,
-  data: CreateExpenseInput,
-  meta: ServiceAuditMeta,
-) {
+export async function createExpense(portId: string, data: CreateExpenseInput, meta: AuditMeta) {
   let amountUsd: string | null = null;
   let exchangeRate: string | null = null;
 
@@ -163,7 +151,7 @@ export async function updateExpense(
   id: string,
   portId: string,
   data: UpdateExpenseInput,
-  meta: ServiceAuditMeta,
+  meta: AuditMeta,
 ) {
   const existing = await getExpenseById(id, portId);
 
@@ -226,7 +214,7 @@ export async function updateExpense(
   return updated;
 }
 
-export async function archiveExpense(id: string, portId: string, meta: ServiceAuditMeta) {
+export async function archiveExpense(id: string, portId: string, meta: AuditMeta) {
   const existing = await getExpenseById(id, portId);
 
   // BR-045: Check if linked to non-draft invoice
@@ -257,7 +245,7 @@ export async function archiveExpense(id: string, portId: string, meta: ServiceAu
   emitToRoom(`port:${portId}`, 'expense:archived', { expenseId: id });
 }
 
-export async function restoreExpense(id: string, portId: string, meta: ServiceAuditMeta) {
+export async function restoreExpense(id: string, portId: string, meta: AuditMeta) {
   await getExpenseById(id, portId);
 
   await restore(expenses, expenses.id, id);
@@ -287,7 +275,7 @@ export async function addReceiptFiles(
   id: string,
   portId: string,
   fileIds: string[],
-  meta: ServiceAuditMeta,
+  meta: AuditMeta,
 ) {
   await getExpenseById(id, portId);
 
diff --git a/src/lib/services/files.ts b/src/lib/services/files.ts
index 0933759..a5fc551 100644
--- a/src/lib/services/files.ts
+++ b/src/lib/services/files.ts
@@ -4,7 +4,7 @@ import { db } from '@/lib/db';
 import { files, documents } from '@/lib/db/schema/documents';
 import { expenses } from '@/lib/db/schema/financial';
 import { berthMaintenanceLog } from '@/lib/db/schema/berths';
-import { createAuditLog } from '@/lib/audit';
+import { createAuditLog, type AuditMeta } from '@/lib/audit';
 import { ConflictError, NotFoundError, ValidationError } from '@/lib/errors';
 import { emitToRoom } from '@/lib/socket/server';
 import { minioClient, getPresignedUrl } from '@/lib/minio';
@@ -20,13 +20,6 @@ import type { UploadFileInput, UpdateFileInput, ListFilesInput } from '@/lib/val
 
 // ─── Types ────────────────────────────────────────────────────────────────────
 
-interface AuditMeta {
-  userId: string;
-  portId: string;
-  ipAddress: string;
-  userAgent: string;
-}
-
 interface UploadFileParams {
   buffer: Buffer;
   originalName: string;
@@ -57,13 +50,9 @@ export async function uploadFile(
   const sanitizedOriginal = sanitizeFilename(file.originalName);
   const sanitizedFilename = sanitizeFilename(data.filename);
 
-  await minioClient.putObject(
-    env.MINIO_BUCKET,
-    storagePath,
-    file.buffer,
-    file.size,
-    { 'Content-Type': file.mimeType },
-  );
+  await minioClient.putObject(env.MINIO_BUCKET, storagePath, file.buffer, file.size, {
+    'Content-Type': file.mimeType,
+  });
 
   const [record] = await db
     .insert(files)
@@ -176,12 +165,7 @@ export async function deleteFile(id: string, portId: string, meta: AuditMeta) {
     db
       .select({ id: expenses.id })
       .from(expenses)
-      .where(
-        and(
-          eq(expenses.portId, portId),
-          arrayContains(expenses.receiptFileIds, [id]),
-        ),
-      )
+      .where(and(eq(expenses.portId, portId), arrayContains(expenses.receiptFileIds, [id])))
       .limit(1),
     db
       .select({ id: berthMaintenanceLog.id })
@@ -196,9 +180,7 @@ export async function deleteFile(id: string, portId: string, meta: AuditMeta) {
   ]);
 
   if (docRefs.length > 0 || expenseRefs.length > 0 || maintenanceRefs.length > 0) {
-    throw new ConflictError(
-      'File cannot be deleted because it is referenced by other records',
-    );
+    throw new ConflictError('File cannot be deleted because it is referenced by other records');
   }
 
   // Delete from MinIO first, then DB
@@ -235,9 +217,7 @@ export async function listFiles(portId: string, query: ListFilesInput) {
   }
 
   const sortColumn =
-    sort === 'filename' ? files.filename :
-    sort === 'sizeBytes' ? files.sizeBytes :
-    files.createdAt;
+    sort === 'filename' ? files.filename : sort === 'sizeBytes' ? files.sizeBytes : files.createdAt;
 
   return buildListQuery({
     table: files,
diff --git a/src/lib/services/interests.service.ts b/src/lib/services/interests.service.ts
index 4c855ff..11bc926 100644
--- a/src/lib/services/interests.service.ts
+++ b/src/lib/services/interests.service.ts
@@ -7,9 +7,10 @@ import { berths } from '@/lib/db/schema/berths';
 import { yachts } from '@/lib/db/schema/yachts';
 import { companyMemberships } from '@/lib/db/schema/companies';
 import { tags } from '@/lib/db/schema/system';
-import { createAuditLog } from '@/lib/audit';
+import { createAuditLog, type AuditMeta } from '@/lib/audit';
 import { NotFoundError, ConflictError, ValidationError } from '@/lib/errors';
 import { emitToRoom } from '@/lib/socket/server';
+import { setEntityTags } from '@/lib/services/entity-tags.helper';
 import { buildListQuery } from '@/lib/db/query-builder';
 import { diffEntity } from '@/lib/entity-diff';
 import { softDelete, restore, withTransaction } from '@/lib/db/utils';
@@ -22,13 +23,6 @@ import type {
 
 // ─── Types ────────────────────────────────────────────────────────────────────
 
-interface AuditMeta {
-  userId: string;
-  portId: string;
-  ipAddress: string;
-  userAgent: string;
-}
-
 // ─── Yacht ownership validator ───────────────────────────────────────────────
 
 async function assertYachtBelongsToClient(
@@ -552,26 +546,18 @@ export async function setInterestTags(
     throw new NotFoundError('Interest');
   }
 
-  await db.delete(interestTags).where(eq(interestTags.interestId, id));
-
-  if (tagIds.length > 0) {
-    await db.insert(interestTags).values(tagIds.map((tagId) => ({ interestId: id, tagId })));
-  }
-
-  void createAuditLog({
-    userId: meta.userId,
-    portId,
-    action: 'update',
-    entityType: 'interest',
+  const result = await setEntityTags({
+    joinTable: interestTags,
+    entityColumn: interestTags.interestId,
+    tagColumn: interestTags.tagId,
     entityId: id,
-    metadata: { type: 'tags_updated', tagIds },
-    ipAddress: meta.ipAddress,
-    userAgent: meta.userAgent,
+    portId,
+    tagIds,
+    meta,
+    entityType: 'interest',
   });
 
-  emitToRoom(`port:${portId}`, 'interest:updated', { interestId: id, changedFields: ['tags'] });
-
-  return { interestId: id, tagIds };
+  return { interestId: result.entityId, tagIds: result.tagIds };
 }
 
 // ─── Link / Unlink Berth ──────────────────────────────────────────────────────
diff --git a/src/lib/services/invoices.ts b/src/lib/services/invoices.ts
index ddca0ab..309c61a 100644
--- a/src/lib/services/invoices.ts
+++ b/src/lib/services/invoices.ts
@@ -9,7 +9,7 @@ import { systemSettings } from '@/lib/db/schema/system';
 import { clients, clientAddresses } from '@/lib/db/schema/clients';
 import { companies, companyAddresses } from '@/lib/db/schema/companies';
 import { buildListQuery } from '@/lib/db/query-builder';
-import { createAuditLog } from '@/lib/audit';
+import { createAuditLog, type AuditMeta } from '@/lib/audit';
 import { diffEntity } from '@/lib/entity-diff';
 import { withTransaction } from '@/lib/db/utils';
 import { NotFoundError, ConflictError, ValidationError } from '@/lib/errors';
@@ -29,14 +29,6 @@ import type {
   ListInvoicesInput,
 } from '@/lib/validators/invoices';
 
-// AuditMeta type expected by service functions
-export interface ServiceAuditMeta {
-  userId: string;
-  portId: string;
-  ipAddress: string;
-  userAgent: string;
-}
-
 // ─── Auto-numbering (BR-041) ───────────────────────────────────────────────
 
 async function generateInvoiceNumber(portId: string, tx: typeof db): Promise<string> {
@@ -218,11 +210,7 @@ export async function getInvoiceById(id: string, portId: string) {
 
 // ─── Create (BR-041, BR-042, BR-045) ─────────────────────────────────────
 
-export async function createInvoice(
-  portId: string,
-  data: CreateInvoiceInput,
-  meta: ServiceAuditMeta,
-) {
+export async function createInvoice(portId: string, data: CreateInvoiceInput, meta: AuditMeta) {
   const invoice = await withTransaction(async (tx) => {
     // Resolve the polymorphic billing entity (client | company). Throws
     // ValidationError if the entity is missing or belongs to another tenant.
@@ -361,7 +349,7 @@ export async function updateInvoice(
   id: string,
   portId: string,
   data: UpdateInvoiceInput,
-  meta: ServiceAuditMeta,
+  meta: AuditMeta,
 ) {
   const existing = await getInvoiceById(id, portId);
   if (existing.status !== 'draft') {
@@ -496,7 +484,7 @@ export async function updateInvoice(
 
 // ─── Delete (draft only) ──────────────────────────────────────────────────
 
-export async function deleteInvoice(id: string, portId: string, meta: ServiceAuditMeta) {
+export async function deleteInvoice(id: string, portId: string, meta: AuditMeta) {
   const existing = await getInvoiceById(id, portId);
   if (existing.status !== 'draft') {
     throw new ConflictError('Only draft invoices can be deleted');
@@ -527,7 +515,7 @@ export async function deleteInvoice(id: string, portId: string, meta: ServiceAud
 
 // ─── Generate PDF ─────────────────────────────────────────────────────────
 
-export async function generateInvoicePdf(id: string, portId: string, meta: ServiceAuditMeta) {
+export async function generateInvoicePdf(id: string, portId: string, meta: AuditMeta) {
   const invoice = await getInvoiceById(id, portId);
 
   const [port] = await db
@@ -589,7 +577,7 @@ export async function generateInvoicePdf(id: string, portId: string, meta: Servi
 
 // ─── Send invoice ─────────────────────────────────────────────────────────
 
-export async function sendInvoice(id: string, portId: string, meta: ServiceAuditMeta) {
+export async function sendInvoice(id: string, portId: string, meta: AuditMeta) {
   const invoice = await getInvoiceById(id, portId);
 
   // Generate PDF if not exists
@@ -637,7 +625,7 @@ export async function recordPayment(
   id: string,
   portId: string,
   data: RecordPaymentInput,
-  meta: ServiceAuditMeta,
+  meta: AuditMeta,
 ) {
   const existing = await getInvoiceById(id, portId);
 
diff --git a/src/lib/services/ports.service.ts b/src/lib/services/ports.service.ts
index a06ed0c..843fde4 100644
--- a/src/lib/services/ports.service.ts
+++ b/src/lib/services/ports.service.ts
@@ -3,18 +3,11 @@ import { eq } from 'drizzle-orm';
 import { db } from '@/lib/db';
 import { ports } from '@/lib/db/schema';
 import type { PortSettings } from '@/lib/db/schema/ports';
-import { createAuditLog } from '@/lib/audit';
+import { createAuditLog, type AuditMeta } from '@/lib/audit';
 import { ConflictError, NotFoundError } from '@/lib/errors';
 import { emitToRoom } from '@/lib/socket/server';
 import type { CreatePortInput, UpdatePortInput } from '@/lib/validators/ports';
 
-interface AuditMeta {
-  userId: string;
-  portId: string;
-  ipAddress: string;
-  userAgent: string;
-}
-
 export async function listPorts() {
   return db.select().from(ports).orderBy(ports.name);
 }
diff --git a/src/lib/services/recommendations.ts b/src/lib/services/recommendations.ts
index 2f398e7..f6bb94e 100644
--- a/src/lib/services/recommendations.ts
+++ b/src/lib/services/recommendations.ts
@@ -5,14 +5,7 @@ import { interests } from '@/lib/db/schema/interests';
 import { yachts } from '@/lib/db/schema/yachts';
 import { berths, berthRecommendations } from '@/lib/db/schema/berths';
 import { NotFoundError } from '@/lib/errors';
-import { createAuditLog } from '@/lib/audit';
-
-interface AuditMeta {
-  userId: string;
-  portId: string;
-  ipAddress: string;
-  userAgent: string;
-}
+import { createAuditLog, type AuditMeta } from '@/lib/audit';
 
 // ─── Score a single berth ─────────────────────────────────────────────────────
 
diff --git a/src/lib/services/reminders.service.ts b/src/lib/services/reminders.service.ts
index fb9563a..e40cecf 100644
--- a/src/lib/services/reminders.service.ts
+++ b/src/lib/services/reminders.service.ts
@@ -2,7 +2,7 @@ import { and, eq, lte, gte, desc, asc, inArray, sql, isNull } from 'drizzle-orm'
 
 import { db } from '@/lib/db';
 import { reminders, interests, clients } from '@/lib/db/schema';
-import { createAuditLog } from '@/lib/audit';
+import { createAuditLog, type AuditMeta } from '@/lib/audit';
 import { NotFoundError, ValidationError } from '@/lib/errors';
 import { emitToRoom } from '@/lib/socket/server';
 import { createNotification } from '@/lib/services/notifications.service';
@@ -14,13 +14,6 @@ import type {
   ReminderListQuery,
 } from '@/lib/validators/reminders';
 
-interface AuditMeta {
-  userId: string;
-  portId: string;
-  ipAddress: string;
-  userAgent: string;
-}
-
 // ─── List ────────────────────────────────────────────────────────────────────
 
 export async function listReminders(portId: string, query: ReminderListQuery) {
diff --git a/src/lib/services/residential.service.ts b/src/lib/services/residential.service.ts
index a5c9056..fb8e9b8 100644
--- a/src/lib/services/residential.service.ts
+++ b/src/lib/services/residential.service.ts
@@ -2,7 +2,7 @@ import { and, eq } from 'drizzle-orm';
 
 import { db } from '@/lib/db';
 import { residentialClients, residentialInterests } from '@/lib/db/schema/residential';
-import { createAuditLog } from '@/lib/audit';
+import { createAuditLog, type AuditMeta } from '@/lib/audit';
 import { NotFoundError } from '@/lib/errors';
 import { emitToRoom } from '@/lib/socket/server';
 import { buildListQuery } from '@/lib/db/query-builder';
@@ -17,13 +17,6 @@ import type {
   UpdateResidentialInterestInput,
 } from '@/lib/validators/residential';
 
-interface AuditMeta {
-  userId: string;
-  portId: string;
-  ipAddress: string;
-  userAgent: string;
-}
-
 // ─── Residential clients ─────────────────────────────────────────────────────
 
 export async function listResidentialClients(portId: string, query: ListResidentialClientsInput) {
diff --git a/src/lib/services/roles.service.ts b/src/lib/services/roles.service.ts
index 32fe3d7..69a224b 100644
--- a/src/lib/services/roles.service.ts
+++ b/src/lib/services/roles.service.ts
@@ -3,18 +3,11 @@ import { eq } from 'drizzle-orm';
 import { db } from '@/lib/db';
 import { roles, userPortRoles } from '@/lib/db/schema';
 import type { RolePermissions } from '@/lib/db/schema/users';
-import { createAuditLog } from '@/lib/audit';
+import { createAuditLog, type AuditMeta } from '@/lib/audit';
 import { ConflictError, NotFoundError, ValidationError } from '@/lib/errors';
 import { emitToRoom } from '@/lib/socket/server';
 import type { CreateRoleInput, UpdateRoleInput } from '@/lib/validators/roles';
 
-interface AuditMeta {
-  userId: string;
-  portId: string;
-  ipAddress: string;
-  userAgent: string;
-}
-
 export async function listRoles() {
   return db.select().from(roles).orderBy(roles.name);
 }
diff --git a/src/lib/services/settings.service.ts b/src/lib/services/settings.service.ts
index 704cd59..bfbd60b 100644
--- a/src/lib/services/settings.service.ts
+++ b/src/lib/services/settings.service.ts
@@ -2,17 +2,10 @@ import { and, eq, isNull } from 'drizzle-orm';
 
 import { db } from '@/lib/db';
 import { systemSettings } from '@/lib/db/schema';
-import { createAuditLog } from '@/lib/audit';
+import { createAuditLog, type AuditMeta } from '@/lib/audit';
 import { NotFoundError } from '@/lib/errors';
 import { emitToRoom } from '@/lib/socket/server';
 
-interface AuditMeta {
-  userId: string;
-  portId: string;
-  ipAddress: string;
-  userAgent: string;
-}
-
 export async function listSettings(portId: string) {
   // Get port-specific settings
   const portSettings = await db
diff --git a/src/lib/services/tags.service.ts b/src/lib/services/tags.service.ts
index 4b0755e..7bd3ecd 100644
--- a/src/lib/services/tags.service.ts
+++ b/src/lib/services/tags.service.ts
@@ -2,31 +2,16 @@ import { and, eq } from 'drizzle-orm';
 
 import { db } from '@/lib/db';
 import { tags } from '@/lib/db/schema';
-import { createAuditLog } from '@/lib/audit';
+import { createAuditLog, type AuditMeta } from '@/lib/audit';
 import { ConflictError, NotFoundError } from '@/lib/errors';
 import { emitToRoom } from '@/lib/socket/server';
 import type { CreateTagInput, UpdateTagInput } from '@/lib/validators/tags';
 
-interface AuditMeta {
-  userId: string;
-  portId: string;
-  ipAddress: string;
-  userAgent: string;
-}
-
 export async function listTags(portId: string) {
-  return db
-    .select()
-    .from(tags)
-    .where(eq(tags.portId, portId))
-    .orderBy(tags.name);
+  return db.select().from(tags).where(eq(tags.portId, portId)).orderBy(tags.name);
 }
 
-export async function createTag(
-  portId: string,
-  data: CreateTagInput,
-  meta: AuditMeta,
-) {
+export async function createTag(portId: string, data: CreateTagInput, meta: AuditMeta) {
   // Enforce unique (portId, name)
   const existing = await db.query.tags.findFirst({
     where: and(eq(tags.portId, portId), eq(tags.name, data.name)),
@@ -60,12 +45,7 @@ export async function createTag(
   return tag!;
 }
 
-export async function updateTag(
-  id: string,
-  portId: string,
-  data: UpdateTagInput,
-  meta: AuditMeta,
-) {
+export async function updateTag(id: string, portId: string, data: UpdateTagInput, meta: AuditMeta) {
   const tag = await db.query.tags.findFirst({
     where: and(eq(tags.id, id), eq(tags.portId, portId)),
   });
@@ -83,7 +63,10 @@ export async function updateTag(
 
   const [updated] = await db
     .update(tags)
-    .set({ ...(data.name ? { name: data.name } : {}), ...(data.color ? { color: data.color } : {}) })
+    .set({
+      ...(data.name ? { name: data.name } : {}),
+      ...(data.color ? { color: data.color } : {}),
+    })
     .where(and(eq(tags.id, id), eq(tags.portId, portId)))
     .returning();
 
@@ -108,11 +91,7 @@ export async function updateTag(
   return updated!;
 }
 
-export async function deleteTag(
-  id: string,
-  portId: string,
-  meta: AuditMeta,
-) {
+export async function deleteTag(id: string, portId: string, meta: AuditMeta) {
   const tag = await db.query.tags.findFirst({
     where: and(eq(tags.id, id), eq(tags.portId, portId)),
   });
diff --git a/src/lib/services/users.service.ts b/src/lib/services/users.service.ts
index f73367f..c3c4f31 100644
--- a/src/lib/services/users.service.ts
+++ b/src/lib/services/users.service.ts
@@ -3,18 +3,11 @@ import { and, eq } from 'drizzle-orm';
 import { db } from '@/lib/db';
 import { user, userProfiles, userPortRoles, roles } from '@/lib/db/schema';
 import { auth } from '@/lib/auth';
-import { createAuditLog } from '@/lib/audit';
+import { createAuditLog, type AuditMeta } from '@/lib/audit';
 import { ConflictError, NotFoundError, ValidationError } from '@/lib/errors';
 import { emitToRoom } from '@/lib/socket/server';
 import type { CreateUserInput, UpdateUserInput } from '@/lib/validators/users';
 
-interface AuditMeta {
-  userId: string;
-  portId: string;
-  ipAddress: string;
-  userAgent: string;
-}
-
 export async function listUsers(portId: string) {
   const rows = await db
     .select({
diff --git a/src/lib/services/webhooks.service.ts b/src/lib/services/webhooks.service.ts
index 0914cbd..5b77ba0 100644
--- a/src/lib/services/webhooks.service.ts
+++ b/src/lib/services/webhooks.service.ts
@@ -3,7 +3,7 @@ import { and, desc, eq, count } from 'drizzle-orm';
 
 import { db } from '@/lib/db';
 import { webhooks, webhookDeliveries } from '@/lib/db/schema/system';
-import { createAuditLog } from '@/lib/audit';
+import { createAuditLog, type AuditMeta } from '@/lib/audit';
 import { encrypt, decrypt } from '@/lib/utils/encryption';
 import { NotFoundError } from '@/lib/errors';
 import { getQueue } from '@/lib/queue';
@@ -16,13 +16,6 @@ import type { WebhookEvent } from '@/lib/services/webhook-event-map';
 
 // ─── Types ────────────────────────────────────────────────────────────────────
 
-interface AuditMeta {
-  userId: string;
-  portId: string;
-  ipAddress: string;
-  userAgent: string;
-}
-
 // ─── Helpers ─────────────────────────────────────────────────────────────────
 
 /** Generates a 32-byte hex secret for signing webhook payloads. */
@@ -173,11 +166,7 @@ export async function updateWebhook(
 
 // ─── Delete ───────────────────────────────────────────────────────────────────
 
-export async function deleteWebhook(
-  portId: string,
-  webhookId: string,
-  meta: AuditMeta,
-) {
+export async function deleteWebhook(portId: string, webhookId: string, meta: AuditMeta) {
   const existing = await db.query.webhooks.findFirst({
     where: eq(webhooks.id, webhookId),
   });
@@ -187,9 +176,7 @@ export async function deleteWebhook(
   }
 
   // CASCADE deletes webhook_deliveries
-  await db
-    .delete(webhooks)
-    .where(and(eq(webhooks.id, webhookId), eq(webhooks.portId, portId)));
+  await db.delete(webhooks).where(and(eq(webhooks.id, webhookId), eq(webhooks.portId, portId)));
 
   void createAuditLog({
     userId: meta.userId,
@@ -205,11 +192,7 @@ export async function deleteWebhook(
 
 // ─── Regenerate Secret ────────────────────────────────────────────────────────
 
-export async function regenerateSecret(
-  portId: string,
-  webhookId: string,
-  meta: AuditMeta,
-) {
+export async function regenerateSecret(portId: string, webhookId: string, meta: AuditMeta) {
   const existing = await db.query.webhooks.findFirst({
     where: eq(webhooks.id, webhookId),
   });
@@ -288,11 +271,7 @@ export async function listDeliveries(
 
 // ─── Send Test Webhook ────────────────────────────────────────────────────────
 
-export async function sendTestWebhook(
-  portId: string,
-  webhookId: string,
-  eventType: WebhookEvent,
-) {
+export async function sendTestWebhook(portId: string, webhookId: string, eventType: WebhookEvent) {
   const webhook = await db.query.webhooks.findFirst({
     where: eq(webhooks.id, webhookId),
   });
diff --git a/src/lib/services/yachts.service.ts b/src/lib/services/yachts.service.ts
index df84f77..d0bf80b 100644
--- a/src/lib/services/yachts.service.ts
+++ b/src/lib/services/yachts.service.ts
@@ -3,9 +3,10 @@ import { db } from '@/lib/db';
 import { yachts, yachtOwnershipHistory, yachtTags, clients } from '@/lib/db/schema';
 import type { Yacht } from '@/lib/db/schema/yachts';
 import { companies } from '@/lib/db/schema/companies';
-import { createAuditLog } from '@/lib/audit';
+import { createAuditLog, type AuditMeta } from '@/lib/audit';
 import { NotFoundError, ValidationError } from '@/lib/errors';
 import { emitToRoom } from '@/lib/socket/server';
+import { setEntityTags } from '@/lib/services/entity-tags.helper';
 import { diffEntity } from '@/lib/entity-diff';
 import { buildListQuery } from '@/lib/db/query-builder';
 import { withTransaction } from '@/lib/db/utils';
@@ -19,13 +20,6 @@ import type {
 
 type CreateYachtInput = z.input<typeof createYachtSchema>;
 
-interface AuditMeta {
-  userId: string;
-  portId: string;
-  ipAddress: string;
-  userAgent: string;
-}
-
 async function assertOwnerExists(
   portId: string,
   owner: { type: 'client' | 'company'; id: string },
@@ -408,22 +402,14 @@ export async function setYachtTags(
   const yacht = await db.query.yachts.findFirst({ where: eq(yachts.id, yachtId) });
   if (!yacht || yacht.portId !== portId) throw new NotFoundError('Yacht');
 
-  await db.delete(yachtTags).where(eq(yachtTags.yachtId, yachtId));
-
-  if (tagIds.length > 0) {
-    await db.insert(yachtTags).values(tagIds.map((tagId) => ({ yachtId, tagId })));
-  }
-
-  void createAuditLog({
-    userId: meta.userId,
-    portId,
-    action: 'update',
-    entityType: 'yacht',
+  await setEntityTags({
+    joinTable: yachtTags,
+    entityColumn: yachtTags.yachtId,
+    tagColumn: yachtTags.tagId,
     entityId: yachtId,
-    newValue: { tagIds },
-    ipAddress: meta.ipAddress,
-    userAgent: meta.userAgent,
+    portId,
+    tagIds,
+    meta,
+    entityType: 'yacht',
   });
-
-  emitToRoom(`port:${portId}`, 'yacht:updated', { yachtId, changedFields: ['tags'] });
 }