feat(currency): centralise money formatting + curated currency picker

New `src/lib/utils/currency.ts` is the single source of truth for
display formatting (`formatCurrency`) and the supported-currency
catalog (`SUPPORTED_CURRENCIES`, 10 codes covering the marina market).

New shared components:
- `<CurrencyInput>` — number input with leading symbol prefix and
  decimal inputMode, raw number value out via onChange.
- `<CurrencySelect>` — Select dropdown over `SUPPORTED_CURRENCIES`
  with symbol + code + label per row, replaces the free-text 3-letter
  inputs that let reps type "EURO" or "$$$" into a 3-char ISO column.

Threaded through every money input + display:
- Forms: berth (price/currency), expense (amount/currency), invoice
  (currency Select + line-items unit-price + step-3 review totals).
- Reads: berth-card / berth-columns / invoice-card / expense-card /
  dashboard KPIs / dashboard revenue-forecast / portal-invoices page.
  Each had its own ad-hoc `Intl.NumberFormat` wrapper with slightly
  different fallbacks; collapsed onto the shared helper.

`InvoiceLineItems` gained a `currency` prop so the unit-price input
prefix and the subtotal use the parent invoice's currency rather than
hard-coded `en-US` formatting.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

src/app/(dashboard)/[portSlug]/invoices/new/page.tsx

@@ -22,8 +22,10 @@ import {
 } from '@/components/ui/select';
 import { Card, CardContent, CardHeader, CardTitle } from '@/components/ui/card';
 import { OwnerPicker } from '@/components/shared/owner-picker';
+import { CurrencySelect } from '@/components/shared/currency-select';
 import { InvoiceLineItems } from '@/components/invoices/invoice-line-items';
 import { apiFetch } from '@/lib/api/client';
+import { formatCurrency } from '@/lib/utils/currency';
 import { createInvoiceSchema, type CreateInvoiceInput } from '@/lib/validators/invoices';
 
 const PAYMENT_TERMS = [
@@ -324,11 +326,10 @@ export default function NewInvoicePage() {
 
                 <div className="space-y-1">
                   <Label>Currency</Label>
-                  <Input
+                  <CurrencySelect
-                    {...register('currency')}
+                    value={watchedValues.currency ?? 'USD'}
-                    placeholder="USD"
+                    onValueChange={(v) => setValue('currency', v, { shouldDirty: true })}
-                    maxLength={3}
+                    className="w-48"
-                    className="uppercase w-24"
                   />
                 </div>
 
@@ -352,7 +353,7 @@ export default function NewInvoicePage() {
                 <CardTitle className="text-base">Line Items</CardTitle>
               </CardHeader>
               <CardContent>
-                <InvoiceLineItems name="lineItems" />
+                <InvoiceLineItems name="lineItems" currency={watchedValues.currency ?? 'USD'} />
                 {errors.lineItems && !Array.isArray(errors.lineItems) && (
                   <p className="text-xs text-destructive mt-2">
                     {(errors.lineItems as { message?: string }).message}
@@ -415,8 +416,10 @@ export default function NewInvoicePage() {
                       <div key={i} className="flex justify-between text-sm">
                         <span>{li.description}</span>
                         <span className="tabular-nums">
-                          {(Number(li.quantity) * Number(li.unitPrice)).toFixed(2)}{' '}
+                          {formatCurrency(
-                          {watchedValues.currency}
+                            Number(li.quantity) * Number(li.unitPrice),
+                            watchedValues.currency,
+                          )}
                         </span>
                       </div>
                     ))}
@@ -427,21 +430,21 @@ export default function NewInvoicePage() {
                   <div className="flex justify-between">
                     <span className="text-muted-foreground">Subtotal</span>
                     <span className="tabular-nums">
-                      {subtotal.toFixed(2)} {watchedValues.currency}
+                      {formatCurrency(subtotal, watchedValues.currency)}
                     </span>
                   </div>
                   {isNet10 && (
                     <div className="flex justify-between text-green-600">
                       <span>Net 10 Discount (~2%)</span>
                       <span className="tabular-nums">
-                        -{discountAmount.toFixed(2)} {watchedValues.currency}
+                        -{formatCurrency(discountAmount, watchedValues.currency)}
                       </span>
                     </div>
                   )}
                   <div className="flex justify-between font-semibold border-t pt-2 mt-1">
                     <span>Total</span>
                     <span className="tabular-nums">
-                      {total.toFixed(2)} {watchedValues.currency}
+                      {formatCurrency(total, watchedValues.currency)}
                     </span>
                   </div>
                 </div>

src/app/(portal)/portal/invoices/page.tsx

@@ -5,6 +5,7 @@ import type { Metadata } from 'next';
 import { getPortalSession } from '@/lib/portal/auth';
 import { getClientInvoices } from '@/lib/services/portal.service';
 import { Badge } from '@/components/ui/badge';
+import { formatCurrency } from '@/lib/utils/currency';
 
 export const metadata: Metadata = { title: 'Invoices' };
 
@@ -16,16 +17,6 @@ const STATUS_COLORS: Record<string, 'default' | 'secondary' | 'destructive' | 'o
   cancelled: 'destructive',
 };
 
-function formatCurrency(amount: string, currency: string): string {
-  const num = parseFloat(amount);
-  if (isNaN(num)) return `${currency} ${amount}`;
-  return new Intl.NumberFormat('en-US', {
-    style: 'currency',
-    currency,
-    minimumFractionDigits: 2,
-  }).format(num);
-}
-
 export default async function PortalInvoicesPage() {
   const session = await getPortalSession();
   if (!session) redirect('/portal/login');

src/components/berths/berth-card.tsx

@@ -13,6 +13,7 @@ import {
 import { TagBadge } from '@/components/shared/tag-badge';
 import { ListCard, ListCardAvatar, ListCardMeta } from '@/components/shared/list-card';
 import { cn } from '@/lib/utils';
+import { formatCurrency } from '@/lib/utils/currency';
 import type { BerthRow } from './berth-columns';
 import { mooringLetterDot } from './mooring-letter-tone';
 
@@ -28,18 +29,6 @@ const STATUS_LABELS: Record<string, string> = {
   sold: 'Sold',
 };
 
-function formatPrice(price: string, currency: string): string {
-  try {
-    return new Intl.NumberFormat('en-US', {
-      style: 'currency',
-      currency: currency || 'USD',
-      maximumFractionDigits: 0,
-    }).format(Number(price));
-  } catch {
-    return `${currency} ${price}`;
-  }
-}
-
 interface BerthCardProps {
   berth: BerthRow;
 }
@@ -66,7 +55,10 @@ export function BerthCard({ berth }: BerthCardProps) {
 
   const metaParts: string[] = [];
   if (dimText) metaParts.push(dimText);
-  if (berth.price) metaParts.push(formatPrice(berth.price, berth.priceCurrency));
+  if (berth.price)
+    metaParts.push(
+      formatCurrency(berth.price, berth.priceCurrency, { maxFractionDigits: 0 }),
+    );
 
   const tags = berth.tags ?? [];
 

src/components/berths/berth-columns.tsx

@@ -12,6 +12,7 @@ import {
   DropdownMenuTrigger,
 } from '@/components/ui/dropdown-menu';
 import { TagBadge } from '@/components/shared/tag-badge';
+import { formatCurrency } from '@/lib/utils/currency';
 import { mooringLetterDot } from './mooring-letter-tone';
 
 export type BerthRow = {
@@ -176,11 +177,7 @@ function joinNonNull(parts: Array<string | null | undefined>, sep = ' · '): str
 
 function formatMoney(amount: string | null, currency: string): string | null {
   if (!amount) return null;
-  return new Intl.NumberFormat('en-US', {
+  return formatCurrency(amount, currency, { maxFractionDigits: 0 });
-    style: 'currency',
-    currency: currency || 'USD',
-    maximumFractionDigits: 0,
-  }).format(Number(amount));
 }
 
 export const berthColumns: ColumnDef<BerthRow, unknown>[] = [

src/components/berths/berth-form.tsx

@@ -20,6 +20,8 @@ import { Sheet, SheetContent, SheetHeader, SheetTitle, SheetFooter } from '@/com
 import { Separator } from '@/components/ui/separator';
 import { Switch } from '@/components/ui/switch';
 import { TagPicker } from '@/components/shared/tag-picker';
+import { CurrencyInput } from '@/components/shared/currency-input';
+import { CurrencySelect } from '@/components/shared/currency-select';
 import { apiFetch } from '@/lib/api/client';
 import { toastError } from '@/lib/api/toast-error';
 import { updateBerthSchema, type UpdateBerthInput } from '@/lib/validators/berths';
@@ -400,11 +402,22 @@ export function BerthForm({ berth, open, onOpenChange }: BerthFormProps) {
             <div className="grid grid-cols-2 gap-4">
               <div className="space-y-2">
                 <Label>Price</Label>
-                <Input type="number" step="0.01" {...register('price')} />
+                <CurrencyInput
+                  value={watch('price') ?? ''}
+                  currency={watch('priceCurrency') ?? 'USD'}
+                  onChange={(v) =>
+                    setValue('price', v ?? undefined, { shouldDirty: true })
+                  }
+                />
               </div>
               <div className="space-y-2">
                 <Label>Currency</Label>
-                <Input {...register('priceCurrency')} placeholder="USD" maxLength={3} />
+                <CurrencySelect
+                  value={watch('priceCurrency') ?? 'USD'}
+                  onValueChange={(v) =>
+                    setValue('priceCurrency', v, { shouldDirty: true })
+                  }
+                />
               </div>
             </div>
           </div>

src/components/dashboard/kpi-cards.tsx

@@ -6,6 +6,7 @@ import { apiFetch } from '@/lib/api/client';
 import { useUIStore } from '@/stores/ui-store';
 import { KPITile } from '@/components/ui/kpi-tile';
 import { Skeleton } from '@/components/ui/skeleton';
+import { formatCurrency } from '@/lib/utils/currency';
 import { WidgetErrorBoundary } from './widget-error-boundary';
 
 interface KpiData {
@@ -15,13 +16,7 @@ interface KpiData {
   occupancyRate: number;
 }
 
-function formatCurrency(value: number): string {
+const formatUsd = (value: number) => formatCurrency(value, 'USD', { maxFractionDigits: 0 });
-  return new Intl.NumberFormat('en-US', {
-    style: 'currency',
-    currency: 'USD',
-    maximumFractionDigits: 0,
-  }).format(value);
-}
 
 function formatPercent(value: number): string {
   return `${value.toFixed(1)}%`;
@@ -81,7 +76,7 @@ export function KpiCards() {
     },
     {
       label: 'Pipeline Value',
-      value: isError ? '-' : formatCurrency(data?.pipelineValueUsd ?? 0),
+      value: isError ? '-' : formatUsd(data?.pipelineValueUsd ?? 0),
       accent: 'success',
     },
     {

src/components/dashboard/revenue-forecast.tsx

@@ -7,6 +7,7 @@ import { Card, CardContent, CardHeader, CardTitle } from '@/components/ui/card';
 import { Badge } from '@/components/ui/badge';
 import { CardSkeleton } from '@/components/shared/loading-skeleton';
 import { stageLabel } from '@/lib/constants';
+import { formatCurrency } from '@/lib/utils/currency';
 import { WidgetErrorBoundary } from './widget-error-boundary';
 
 interface StageBreakdownRow {
@@ -21,13 +22,7 @@ interface ForecastData {
   weightsSource: 'db' | 'default';
 }
 
-function formatCurrency(value: number): string {
+const formatUsd = (value: number) => formatCurrency(value, 'USD', { maxFractionDigits: 0 });
-  return new Intl.NumberFormat('en-US', {
-    style: 'currency',
-    currency: 'USD',
-    maximumFractionDigits: 0,
-  }).format(value);
-}
 
 function RevenueForecastInner() {
   const { data, isLoading } = useQuery<ForecastData>({
@@ -56,7 +51,7 @@ function RevenueForecastInner() {
       <CardContent className="space-y-4">
         <div>
           <p className="text-xs text-muted-foreground">Weighted Pipeline Value</p>
-          <p className="text-2xl font-bold">{formatCurrency(data?.totalWeightedValue ?? 0)}</p>
+          <p className="text-2xl font-bold">{formatUsd(data?.totalWeightedValue ?? 0)}</p>
         </div>
 
         {activeStages.length > 0 && (
@@ -67,7 +62,7 @@ function RevenueForecastInner() {
                   {stageLabel(s.stage)}
                   <span className="ml-1 text-xs">({s.count})</span>
                 </span>
-                <span className="font-medium tabular-nums">{formatCurrency(s.weightedValue)}</span>
+                <span className="font-medium tabular-nums">{formatUsd(s.weightedValue)}</span>
               </div>
             ))}
           </div>

src/components/expenses/expense-card.tsx

@@ -13,6 +13,7 @@ import {
 } from '@/components/ui/dropdown-menu';
 import { ListCard, ListCardAvatar, ListCardMeta } from '@/components/shared/list-card';
 import { cn } from '@/lib/utils';
+import { formatCurrency } from '@/lib/utils/currency';
 import type { ExpenseRow } from './expense-columns';
 
 const PAYMENT_STATUS_COLORS: Record<string, string> = {
@@ -47,13 +48,7 @@ function deriveAccent(status: string | null, duplicateOf: string | null): string
   }
 }
 
-function formatAmount(amount: string, currency: string): string {
+const formatAmount = (amount: string, currency: string) => formatCurrency(amount, currency);
-  try {
-    return new Intl.NumberFormat('en', { style: 'currency', currency }).format(Number(amount));
-  } catch {
-    return `${currency} ${amount}`;
-  }
-}
 
 interface ExpenseCardProps {
   expense: ExpenseRow;

src/components/expenses/expense-form-dialog.tsx

@@ -19,6 +19,8 @@ import {
   SelectValue,
 } from '@/components/ui/select';
 import { Sheet, SheetContent, SheetHeader, SheetTitle, SheetFooter } from '@/components/ui/sheet';
+import { CurrencyInput } from '@/components/shared/currency-input';
+import { CurrencySelect } from '@/components/shared/currency-select';
 import { apiFetch } from '@/lib/api/client';
 import { createExpenseSchema, type CreateExpenseInput } from '@/lib/validators/expenses';
 import { EXPENSE_CATEGORIES, PAYMENT_METHODS } from '@/lib/constants';
@@ -50,6 +52,7 @@ export function ExpenseFormDialog({ open, onOpenChange, expense }: ExpenseFormDi
     handleSubmit,
     setValue,
     reset,
+    watch,
     formState: { errors, isSubmitting },
   } = useForm<CreateExpenseInput>({
     resolver: zodResolver(createExpenseSchema),
@@ -215,20 +218,26 @@ export function ExpenseFormDialog({ open, onOpenChange, expense }: ExpenseFormDi
           <div className="grid grid-cols-2 gap-3">
             <div className="space-y-2">
               <Label htmlFor="amount">Amount *</Label>
-              <Input
+              <CurrencyInput
                 id="amount"
-                type="number"
+                value={watch('amount') ?? ''}
-                step="0.01"
+                currency={watch('currency') ?? 'USD'}
-                min="0"
+                onChange={(v) =>
-                placeholder="0.00"
+                  setValue('amount', v ?? Number.NaN, { shouldDirty: true, shouldValidate: true })
-                {...register('amount', { valueAsNumber: true })}
+                }
               />
               {errors.amount && <p className="text-xs text-destructive">{errors.amount.message}</p>}
             </div>
 
             <div className="space-y-2">
               <Label htmlFor="currency">Currency</Label>
-              <Input id="currency" placeholder="USD" maxLength={3} {...register('currency')} />
+              <CurrencySelect
+                id="currency"
+                value={watch('currency') ?? 'USD'}
+                onValueChange={(v) =>
+                  setValue('currency', v, { shouldDirty: true })
+                }
+              />
               {errors.currency && (
                 <p className="text-xs text-destructive">{errors.currency.message}</p>
               )}

src/components/invoices/invoice-card.tsx

@@ -22,6 +22,7 @@ import {
 } from '@/components/ui/dropdown-menu';
 import { ListCard, ListCardAvatar, ListCardMeta } from '@/components/shared/list-card';
 import { cn } from '@/lib/utils';
+import { formatCurrency } from '@/lib/utils/currency';
 import type { InvoiceRow } from './invoice-columns';
 
 const STATUS_COLORS: Record<string, string> = {
@@ -48,13 +49,7 @@ const STATUS_ACCENT: Record<string, string> = {
   cancelled: 'bg-slate-200',
 };
 
-function formatAmount(total: string, currency: string): string {
+const formatAmount = (total: string, currency: string) => formatCurrency(total, currency);
-  try {
-    return new Intl.NumberFormat('en', { style: 'currency', currency }).format(Number(total));
-  } catch {
-    return `${currency} ${total}`;
-  }
-}
 
 interface InvoiceCardProps {
   invoice: InvoiceRow;

src/components/invoices/invoice-line-items.tsx

@@ -5,6 +5,8 @@ import { Plus, Trash2 } from 'lucide-react';
 
 import { Button } from '@/components/ui/button';
 import { Input } from '@/components/ui/input';
+import { CurrencyInput } from '@/components/shared/currency-input';
+import { formatCurrency } from '@/lib/utils/currency';
 
 interface LineItem {
   description: string;
@@ -14,10 +16,13 @@ interface LineItem {
 
 interface InvoiceLineItemsProps {
   name?: string;
+  /** Currency code from the parent invoice form (drives both the
+   *  unit-price input symbol and the subtotal formatting). */
+  currency?: string;
 }
 
-export function InvoiceLineItems({ name = 'lineItems' }: InvoiceLineItemsProps) {
+export function InvoiceLineItems({ name = 'lineItems', currency = 'USD' }: InvoiceLineItemsProps) {
-  const { register, watch } = useFormContext();
+  const { register, setValue, watch } = useFormContext();
   const { fields, append, remove } = useFieldArray({ name });
 
   const lineItems: LineItem[] = watch(name) ?? [];
@@ -66,22 +71,18 @@ export function InvoiceLineItems({ name = 'lineItems' }: InvoiceLineItemsProps)
               />
             </div>
             <div className="col-span-2">
-              <Input
+              <CurrencyInput
-                {...register(`${name}.${index}.unitPrice`, { valueAsNumber: true })}
+                value={lineItems[index]?.unitPrice ?? null}
-                type="number"
+                currency={currency}
-                min="0"
+                onChange={(v) =>
+                  setValue(`${name}.${index}.unitPrice`, v ?? 0, { shouldDirty: true })
+                }
                 step="any"
-                placeholder="0.00"
                 className="h-8 text-sm text-right"
               />
             </div>
             <div className="col-span-1 flex items-center justify-end h-8">
-              <span className="text-sm tabular-nums">
+              <span className="text-sm tabular-nums">{formatCurrency(lineTotal, currency)}</span>
-                {lineTotal.toLocaleString('en-US', {
-                  minimumFractionDigits: 2,
-                  maximumFractionDigits: 2,
-                })}
-              </span>
             </div>
             <div className="col-span-1 flex items-center justify-end h-8">
               <Button
@@ -120,13 +121,7 @@ export function InvoiceLineItems({ name = 'lineItems' }: InvoiceLineItemsProps)
         </Button>
         {fields.length > 0 && (
           <div className="text-sm font-medium">
-            Subtotal:{' '}
+            Subtotal: <span className="tabular-nums">{formatCurrency(subtotal, currency)}</span>
-            <span className="tabular-nums">
-              {subtotal.toLocaleString('en-US', {
-                minimumFractionDigits: 2,
-                maximumFractionDigits: 2,
-              })}
-            </span>
           </div>
         )}
       </div>

src/components/shared/currency-input.tsx

@@ -0,0 +1,66 @@
+'use client';
+
+import * as React from 'react';
+
+import { Input } from '@/components/ui/input';
+import { cn } from '@/lib/utils';
+import { currencySymbol } from '@/lib/utils/currency';
+
+interface CurrencyInputProps
+  extends Omit<React.ComponentProps<'input'>, 'value' | 'onChange' | 'type'> {
+  /** Controlled raw numeric value. `null` / `undefined` render empty. */
+  value: number | string | null | undefined;
+  /** Fires with a raw number (or `null` if cleared). */
+  onChange: (value: number | null) => void;
+  /** ISO currency code; renders as a leading symbol prefix. */
+  currency?: string;
+  className?: string;
+}
+
+/**
+ * Numeric input pre-decorated with a currency symbol. The display
+ * value is the raw number the user typed (we don't fight the keystroke
+ * cadence by re-formatting on every key) — formatted display lives in
+ * read-only contexts via `formatCurrency()`. This keeps form behaviour
+ * predictable while still scoping the input to a money field via the
+ * symbol prefix and the `decimal` inputMode.
+ */
+export const CurrencyInput = React.forwardRef<HTMLInputElement, CurrencyInputProps>(
+  ({ value, onChange, currency = 'USD', className, ...props }, ref) => {
+    const symbol = currencySymbol(currency);
+
+    const display =
+      value === null || value === undefined || value === '' ? '' : String(value);
+
+    return (
+      <div className="relative">
+        <span
+          className="pointer-events-none absolute left-3 top-1/2 -translate-y-1/2 text-sm text-muted-foreground"
+          aria-hidden
+        >
+          {symbol}
+        </span>
+        <Input
+          ref={ref}
+          type="number"
+          inputMode="decimal"
+          step="0.01"
+          min="0"
+          value={display}
+          onChange={(e) => {
+            const raw = e.target.value;
+            if (raw === '') {
+              onChange(null);
+              return;
+            }
+            const n = Number(raw);
+            onChange(Number.isFinite(n) ? n : null);
+          }}
+          className={cn('pl-9 tabular-nums', className)}
+          {...props}
+        />
+      </div>
+    );
+  },
+);
+CurrencyInput.displayName = 'CurrencyInput';

src/components/shared/currency-select.tsx

@@ -0,0 +1,48 @@
+'use client';
+
+import {
+  Select,
+  SelectContent,
+  SelectItem,
+  SelectTrigger,
+  SelectValue,
+} from '@/components/ui/select';
+import { SUPPORTED_CURRENCIES } from '@/lib/utils/currency';
+
+interface CurrencySelectProps {
+  value: string | undefined;
+  onValueChange: (value: string) => void;
+  disabled?: boolean;
+  id?: string;
+  className?: string;
+}
+
+/**
+ * Select dropdown over the curated `SUPPORTED_CURRENCIES` list. Replaces
+ * the free-text `<Input maxLength={3}>` price-currency spots so reps
+ * can't typo "EURO" or "$$$" into a 3-letter ISO column.
+ */
+export function CurrencySelect({
+  value,
+  onValueChange,
+  disabled,
+  id,
+  className,
+}: CurrencySelectProps) {
+  return (
+    <Select value={value} onValueChange={onValueChange} disabled={disabled}>
+      <SelectTrigger id={id} className={className}>
+        <SelectValue placeholder="Select currency" />
+      </SelectTrigger>
+      <SelectContent>
+        {SUPPORTED_CURRENCIES.map((c) => (
+          <SelectItem key={c.code} value={c.code}>
+            <span className="tabular-nums mr-2">{c.symbol}</span>
+            <span className="font-medium">{c.code}</span>
+            <span className="text-muted-foreground ml-2 text-xs">{c.label}</span>
+          </SelectItem>
+        ))}
+      </SelectContent>
+    </Select>
+  );
+}

src/lib/utils/currency.ts

@@ -0,0 +1,71 @@
+/**
+ * Single source of truth for money formatting + the supported-currency
+ * dropdown list. Everywhere in the CRM that renders an amount should
+ * call `formatCurrency()` rather than spinning up its own
+ * `Intl.NumberFormat`, and every form that captures an amount should
+ * use the curated `SUPPORTED_CURRENCIES` list rather than a free-text
+ * 3-letter input.
+ */
+
+export const SUPPORTED_CURRENCIES = [
+  { code: 'USD', symbol: '$', label: 'US Dollar' },
+  { code: 'EUR', symbol: '€', label: 'Euro' },
+  { code: 'GBP', symbol: '£', label: 'British Pound' },
+  { code: 'CAD', symbol: 'CA$', label: 'Canadian Dollar' },
+  { code: 'AUD', symbol: 'A$', label: 'Australian Dollar' },
+  { code: 'CHF', symbol: 'CHF', label: 'Swiss Franc' },
+  { code: 'JPY', symbol: '¥', label: 'Japanese Yen' },
+  { code: 'AED', symbol: 'د.إ', label: 'UAE Dirham' },
+  { code: 'SGD', symbol: 'S$', label: 'Singapore Dollar' },
+  { code: 'HKD', symbol: 'HK$', label: 'Hong Kong Dollar' },
+] as const;
+
+export type SupportedCurrencyCode = (typeof SUPPORTED_CURRENCIES)[number]['code'];
+
+const SUPPORTED_SET: ReadonlySet<string> = new Set(SUPPORTED_CURRENCIES.map((c) => c.code));
+
+/**
+ * Format an amount for display. Accepts numbers, numeric strings, and
+ * null/undefined (returns the empty string for the latter so callers
+ * can short-circuit display logic).
+ *
+ * Defaults to `en-US` locale because the CRM is single-locale today;
+ * pass `locale` explicitly when rendering for portal users in the
+ * future. Unknown ISO codes fall through to Intl unchanged so the
+ * function never throws on legacy data.
+ */
+export function formatCurrency(
+  amount: number | string | null | undefined,
+  currency: string | null | undefined = 'USD',
+  options: { locale?: string; minFractionDigits?: number; maxFractionDigits?: number } = {},
+): string {
+  if (amount === null || amount === undefined || amount === '') return '';
+  const value = typeof amount === 'number' ? amount : Number(amount);
+  if (!Number.isFinite(value)) return '';
+  const code = (currency ?? 'USD').toUpperCase();
+  const { locale = 'en-US', minFractionDigits = 2, maxFractionDigits = 2 } = options;
+  try {
+    return new Intl.NumberFormat(locale, {
+      style: 'currency',
+      currency: code,
+      minimumFractionDigits: minFractionDigits,
+      maximumFractionDigits: maxFractionDigits,
+    }).format(value);
+  } catch {
+    // Unknown currency code — degrade to a bare number with the code
+    // appended rather than throwing. Keeps display robust against any
+    // legacy NocoDB rows that smuggled non-ISO strings into the column.
+    return `${value.toFixed(maxFractionDigits)} ${code}`;
+  }
+}
+
+/** Whether a 3-letter code is in the curated supported list. */
+export function isSupportedCurrency(code: string): boolean {
+  return SUPPORTED_SET.has(code.toUpperCase());
+}
+
+/** Symbol for a given currency code, falling back to the code itself. */
+export function currencySymbol(code: string): string {
+  const match = SUPPORTED_CURRENCIES.find((c) => c.code === code.toUpperCase());
+  return match?.symbol ?? code.toUpperCase();
+}