diff --git a/apps/hq/src/api.ts b/apps/hq/src/api.ts
index 9eee431..d3f44a9 100644
--- a/apps/hq/src/api.ts
+++ b/apps/hq/src/api.ts
@@ -60,7 +60,7 @@ import {
 import { pullMonthlyCosts } from './aws-costs'
 import { clientProfitability, duesAging, gstSummary, moduleRevenue, type DateRange } from './repos-reports'
 import { listUsageRateCards, setUsageRateCard } from './repos-rate-card'
-import { renewalsDue, generateModuleRenewalQuote } from './repos-renewals'
+import { renewalsDue, generateModuleRenewalQuote, generateBulkSmsPurchaseQuote } from './repos-renewals'
 import { misCockpit } from './repos-mis'
 import { smsBalances, refreshSmsBalance, refreshAllSmsBalances, DEFAULT_SMS_BALANCE_API } from './repos-sms'
 import { globalSearch } from './repos-search'
@@ -1665,6 +1665,16 @@ export function apiRouter(
       res.status(400).json({ ok: false, error: err instanceof Error ? err.message : String(err) })
     }
   })
+  // Ad-hoc bulk SMS credit purchase (top-up) — distinct from a subscription renewal.
+  r.post('/client-modules/:id/bulk-sms-quote', requireAuth, async (req, res) => {
+    try {
+      const qty = Number((req.body as { smsQty?: unknown }).smsQty)
+      const doc = await generateBulkSmsPurchaseQuote(db, staffId(res), String(req.params['id'] ?? ''), qty)
+      res.json({ ok: true, document: doc })
+    } catch (err) {
+      res.status(400).json({ ok: false, error: err instanceof Error ? err.message : String(err) })
+    }
+  })
 
   // ---------- bulk operations (D26 — cleanup at scale, owner-only) ----------
   r.post('/clients/bulk', requireAuth, requireOwner, async (req, res) => {
diff --git a/apps/hq/src/repos-documents.ts b/apps/hq/src/repos-documents.ts
index ba02a91..7245131 100644
--- a/apps/hq/src/repos-documents.ts
+++ b/apps/hq/src/repos-documents.ts
@@ -152,6 +152,8 @@ export interface DraftInput {
   terms?: string
   /** INVOICE only (D18): payment due date; when absent, issue stamps doc_date + terms. */
   dueDate?: string
+  /** Provenance tag for the frontend's Quote/Renewal/Bulk-top-up label; default: schema default ('hq'). */
+  source?: string
 }
 
 const todayIso = (): string => new Date().toISOString().slice(0, 10)
@@ -240,18 +242,18 @@ async function buildLines(db: DB, inputs: DraftLineInput[], onDate: string, warn
 /** Insert a draft row + created event + audit. Callers wrap in a transaction. */
 async function insertDocRow(db: DB, userId: string, a: {
   docType: DocType; clientId: string; refDocId: string | null; docDate: string
-  totals: BillTotals; payload: DocPayload; dueDate?: string | null
+  totals: BillTotals; payload: DocPayload; dueDate?: string | null; source?: string
 }): Promise<Doc> {
   const id = uuidv7()
   const t = a.totals
   await db.run(
     `INSERT INTO document (id, doc_type, doc_no, fy, client_id, doc_date, due_date, status, ref_doc_id,
        taxable_paise, cgst_paise, sgst_paise, igst_paise, round_off_paise, payable_paise,
-       payload, created_by, created_at)
-     VALUES (?, ?, NULL, ?, ?, ?, ?, 'draft', ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)`,
+       payload, source, created_by, created_at)
+     VALUES (?, ?, NULL, ?, ?, ?, ?, 'draft', ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)`,
     id, a.docType, fyOf(a.docDate), a.clientId, a.docDate, a.dueDate ?? null, a.refDocId,
     t.taxablePaise, t.cgstPaise, t.sgstPaise, t.igstPaise, t.roundOffPaise, t.payablePaise,
-    JSON.stringify(a.payload), userId, new Date().toISOString())
+    JSON.stringify(a.payload), a.source ?? 'hq', userId, new Date().toISOString())
   await addEvent(db, id, 'created', a.refDocId !== null ? { refDocId: a.refDocId } : {})
   const doc = (await getDocument(db, id))!
   await writeAudit(db, userId, 'create', 'document', id, undefined, {
@@ -334,7 +336,7 @@ export async function createDraft(db: DB, userId: string, input: DraftInput): Pr
   return db.transaction(() => insertDocRow(db, userId, {
     docType: prepared.docType, clientId: prepared.clientId, refDocId: null,
     docDate: prepared.docDate, totals: prepared.totals, payload: prepared.payload,
-    dueDate: prepared.dueDate ?? null,
+    dueDate: prepared.dueDate ?? null, source: input.source,
   }))
 }
 
diff --git a/apps/hq/src/repos-renewals.ts b/apps/hq/src/repos-renewals.ts
index a5edc42..e3e8180 100644
--- a/apps/hq/src/repos-renewals.ts
+++ b/apps/hq/src/repos-renewals.ts
@@ -72,7 +72,26 @@ export async function generateModuleRenewalQuote(db: DB, userId: string, clientM
   const cm = await getClientModule(db, clientModuleId)
   if (cm === null) throw new Error('Client module not found')
   return createDraft(db, userId, {
-    docType: 'PROFORMA', clientId: cm.clientId,
+    docType: 'PROFORMA', clientId: cm.clientId, source: 'module_renewal',
     lines: [{ moduleId: cm.moduleId, qty: 1, kind: cm.kind, edition: cm.edition }],
   })
 }
+
+/**
+ * Ad-hoc bulk SMS credit purchase (top-up) — a PROFORMA priced through the same
+ * createDraft path as any other document, so the usage rate card (D23) resolves the
+ * per-SMS rate for `smsQty` the same way a subscription line would. Tagged
+ * `source: 'bulk_sms_topup'` so it reads distinctly from a subscription renewal
+ * (`module_renewal`) on the client-detail document list.
+ */
+export async function generateBulkSmsPurchaseQuote(
+  db: DB, userId: string, clientModuleId: string, smsQty: number,
+): Promise<Doc> {
+  if (!Number.isInteger(smsQty) || smsQty <= 0) throw new Error('SMS quantity must be a positive integer')
+  const cm = await getClientModule(db, clientModuleId)
+  if (cm === null) throw new Error('Client module not found')
+  return createDraft(db, userId, {
+    docType: 'PROFORMA', clientId: cm.clientId, source: 'bulk_sms_topup',
+    lines: [{ moduleId: cm.moduleId, qty: smsQty, kind: cm.kind, edition: cm.edition }],
+  })
+}
diff --git a/apps/hq/test/bulk-sms-purchase.test.ts b/apps/hq/test/bulk-sms-purchase.test.ts
new file mode 100644
index 0000000..fdee684
--- /dev/null
+++ b/apps/hq/test/bulk-sms-purchase.test.ts
@@ -0,0 +1,74 @@
+// apps/hq/test/bulk-sms-purchase.test.ts — Task 7: ad-hoc bulk-SMS top-up documents,
+// tagged distinctly from subscription renewals via document.source.
+import { describe, it, expect } from 'vitest'
+import { openDb } from '../src/db'
+import { seedIfEmpty } from '../src/seed'
+import { createClient } from '../src/repos-clients'
+import { createModule, assignModule, setPrice, updateClientModule } from '../src/repos-modules'
+import { setUsageRateCard } from '../src/repos-rate-card'
+import { generateModuleRenewalQuote, generateBulkSmsPurchaseQuote } from '../src/repos-renewals'
+import { createDraft, getDocument } from '../src/repos-documents'
+
+// The founder's real card: ₹0.40 / 0.37 / 0.34 / 0.30 per SMS = 40/37/34/30 paise.
+const BANDS = [
+  { minQty: 50_000, ratePaise: 40 },
+  { minQty: 100_000, ratePaise: 37 },
+  { minQty: 200_000, ratePaise: 34 },
+  { minQty: 300_000, ratePaise: 30 },
+]
+
+async function world() {
+  const db = openDb(':memory:')
+  await seedIfEmpty(db) // company state 32, GST18
+  const c = await createClient(db, 'u1', { name: 'Karapuzha SCB', stateCode: '32' })
+  const sms = await createModule(db, 'u1', { code: 'SMS', name: 'Bulk SMS', allowedKinds: ['usage'] })
+  await setUsageRateCard(db, 'u1', sms.id, '2026-04-01', BANDS)
+  const cm = await assignModule(db, 'u1', { clientId: c.id, moduleId: sms.id, kind: 'usage' })
+  return { db, c, sms, cm }
+}
+
+describe('generateBulkSmsPurchaseQuote', () => {
+  it('raises a proforma tagged bulk_sms_topup for the given SMS quantity', async () => {
+    const { db, cm } = await world()
+    const doc = await generateBulkSmsPurchaseQuote(db, 'u1', cm.id, 100_000)
+    expect(doc.docType).toBe('PROFORMA')
+    expect(doc.source).toBe('bulk_sms_topup')
+    expect(doc.payload.lines[0]!.qty).toBe(100_000)
+    expect(doc.payablePaise).toBeGreaterThan(0)
+    // Persisted correctly — a re-fetch from the DB carries the same tag.
+    const full = (await getDocument(db, doc.id))!
+    expect(full.source).toBe('bulk_sms_topup')
+  })
+
+  it('rejects a non-positive or fractional quantity', async () => {
+    const { db, cm } = await world()
+    await expect(generateBulkSmsPurchaseQuote(db, 'u1', cm.id, 0)).rejects.toThrow()
+    await expect(generateBulkSmsPurchaseQuote(db, 'u1', cm.id, -5)).rejects.toThrow()
+    await expect(generateBulkSmsPurchaseQuote(db, 'u1', cm.id, 1.5)).rejects.toThrow()
+  })
+
+  it('rejects an unknown client module', async () => {
+    const { db } = await world()
+    await expect(generateBulkSmsPurchaseQuote(db, 'u1', 'nope', 100_000)).rejects.toThrow(/not found/)
+  })
+})
+
+describe('document.source tagging', () => {
+  it('tags a renewal proforma module_renewal, and a manual draft keeps the default', async () => {
+    const { db, c } = await world()
+    // A separate yearly-priced module for the renewal path (usage modules enforce a
+    // minimum-order qty that a qty:1 renewal line would fail).
+    const yearly = await createModule(db, 'u1', { code: 'CORE', name: 'Core App', allowedKinds: ['yearly'] })
+    await setPrice(db, 'u1', { moduleId: yearly.id, kind: 'yearly', pricePaise: 10_000_00, effectiveFrom: '2026-01-01' })
+    const cm2 = await assignModule(db, 'u1', { clientId: c.id, moduleId: yearly.id, kind: 'yearly' })
+    await updateClientModule(db, 'u1', cm2.id, { nextRenewal: '2026-08-15' })
+    const renewal = await generateModuleRenewalQuote(db, 'u1', cm2.id)
+    expect(renewal.source).toBe('module_renewal')
+
+    const manual = await createDraft(db, 'u1', {
+      docType: 'PROFORMA', clientId: c.id,
+      lines: [{ moduleId: yearly.id, qty: 1, kind: 'yearly' }],
+    })
+    expect(manual.source).toBe('hq') // default preserved when source is omitted
+  })
+})