diff --git a/src/jobs/processors/documenso-poll.ts b/src/jobs/processors/documenso-poll.ts
index 73fd1e91..e7df28ce 100644
--- a/src/jobs/processors/documenso-poll.ts
+++ b/src/jobs/processors/documenso-poll.ts
@@ -9,8 +9,25 @@ import {
   handleDocumentExpired,
   handleDocumentRejected,
 } from '@/lib/services/documents.service';
+import { getPortDocumensoConfig, type DocumensoApiVersion } from '@/lib/services/port-config';
 import { logger } from '@/lib/logger';
 
+/**
+ * Whether a document's `documensoId` can be fetched under the port's current
+ * Documenso API version. A v2 envelope id is the public `envelope_xxx` string;
+ * a legacy v1 id is a bare numeric (e.g. "46"). The v2 `/api/v2/envelope/{id}`
+ * endpoint rejects numerics with a 400 "Invalid envelope ID", so a port that
+ * has cut over to v2 must SKIP its old v1 documents in the poll instead of
+ * erroring on every cycle. Ports still on the v1 API keep polling numeric ids.
+ */
+export function isPollableDocumensoId(
+  documensoId: string,
+  apiVersion: DocumensoApiVersion,
+): boolean {
+  if (apiVersion === 'v2' && !documensoId.startsWith('envelope_')) return false;
+  return true;
+}
+
 export async function processDocumensoPoll(): Promise<void> {
   // Find all documents that are in-progress signing and have a documensoId
   const pendingDocs = await db.query.documents.findMany({
@@ -24,9 +41,25 @@ export async function processDocumensoPoll(): Promise<void> {
 
   logger.info({ count: pendingDocs.length }, 'Polling Documenso for document statuses');
 
+  // Per-port API version, resolved once per port (cheap memo for the run).
+  const apiVersionByPort = new Map<string, DocumensoApiVersion>();
+  let skippedLegacy = 0;
+
   for (const doc of pendingDocs) {
     if (!doc.documensoId) continue;
 
+    let apiVersion = apiVersionByPort.get(doc.portId);
+    if (!apiVersion) {
+      apiVersion = (await getPortDocumensoConfig(doc.portId)).apiVersion;
+      apiVersionByPort.set(doc.portId, apiVersion);
+    }
+    // Skip legacy v1 documents the port's v2 API can't resolve — otherwise each
+    // poll cycle 400s ("Invalid envelope ID") on abandoned pre-cutover docs.
+    if (!isPollableDocumensoId(doc.documensoId, apiVersion)) {
+      skippedLegacy++;
+      continue;
+    }
+
     try {
       // Pass the doc's portId so the client uses per-port credentials
       // (admin-set Documenso URL/key/version), not the global env fallback.
@@ -112,4 +145,11 @@ export async function processDocumensoPoll(): Promise<void> {
       );
     }
   }
+
+  if (skippedLegacy > 0) {
+    logger.info(
+      { skippedLegacy },
+      'Documenso poll: skipped legacy v1 documents not resolvable on the v2 API',
+    );
+  }
 }
diff --git a/tests/unit/documenso-poll.test.ts b/tests/unit/documenso-poll.test.ts
new file mode 100644
index 00000000..fc47a75e
--- /dev/null
+++ b/tests/unit/documenso-poll.test.ts
@@ -0,0 +1,21 @@
+import { describe, it, expect } from 'vitest';
+
+import { isPollableDocumensoId } from '@/jobs/processors/documenso-poll';
+
+describe('isPollableDocumensoId', () => {
+  it('skips legacy v1 numeric ids when the port is on the v2 API', () => {
+    // Real prod offenders: abandoned June-3 v1 EOIs whose documenso_id is "46"/"85"/"88".
+    // The v2 /api/v2/envelope/{id} endpoint rejects bare numerics ("Invalid envelope ID").
+    expect(isPollableDocumensoId('46', 'v2')).toBe(false);
+    expect(isPollableDocumensoId('125', 'v2')).toBe(false);
+  });
+
+  it('polls real v2 envelope ids on the v2 API', () => {
+    expect(isPollableDocumensoId('envelope_ydshkombscbhfnfd', 'v2')).toBe(true);
+  });
+
+  it('still polls numeric ids for a port that is on the v1 API', () => {
+    expect(isPollableDocumensoId('46', 'v1')).toBe(true);
+    expect(isPollableDocumensoId('envelope_abc', 'v1')).toBe(true);
+  });
+});