diff --git a/backend/__tests__/integration/bookingCutover.test.js b/backend/__tests__/integration/bookingCutover.test.js
index 3f4d7764..563d4fd6 100644
--- a/backend/__tests__/integration/bookingCutover.test.js
+++ b/backend/__tests__/integration/bookingCutover.test.js
@@ -99,6 +99,40 @@ describe('booking cutover — draft invoices on hold', () => {
     expect(inv.scheduled_send_at == null).toBe(true); // still held — no auto-send
   });
 
+  it('finalizeQuoteResponses only fires once the 15-min response window has locked', async () => {
+    const mk = async (lockOffsetMs) => {
+      const dealUuid = crypto.randomUUID();
+      const [id] = await db('quotes').insert({
+        quote_number: `Q-${dealUuid.slice(0, 8)}`,
+        customer_account_id: customerId,
+        status: 'accepted',
+        currency: 'CHF', issue_date: '2026-01-01',
+        net_amount_minor: 1000, vat_amount_minor: 0, shipping_amount_minor: 0, total_amount_minor: 1000,
+        responded_at: new Date().toISOString(),
+        response_locked_at: new Date(Date.now() + lockOffsetMs).toISOString(),
+        accepted_at: new Date().toISOString(),
+        deal_uuid: dealUuid,
+        created_by_admin_id: adminId,
+      });
+      return id;
+    };
+    const openId = await mk(15 * 60 * 1000);   // still inside the window
+    const lockedId = await mk(-60 * 1000);      // window already closed
+
+    const emitted = await quoteService.finalizeQuoteResponses();
+    expect(emitted).toBeGreaterThanOrEqual(1);
+
+    const open = await db('quotes').where({ id: openId }).first();
+    const locked = await db('quotes').where({ id: lockedId }).first();
+    expect(open.workflow_response_emitted_at == null).toBe(true);   // deferred — not yet fired
+    expect(locked.workflow_response_emitted_at == null).toBe(false); // fired + stamped
+
+    // Idempotent: a second sweep doesn't re-fire the already-stamped one.
+    const again = await db('quotes').where({ id: lockedId })
+      .whereNull('workflow_response_emitted_at').update({ workflow_response_emitted_at: new Date() });
+    expect(again).toBe(0);
+  });
+
   it('reserve_date path (convertToEvent skipInvoices) creates a draft event with NO invoices', async () => {
     const quoteId = await acceptedQuote();
     const res = await quoteService.convertToEvent(quoteId, adminId, { hold: true, skipInvoices: true });
diff --git a/backend/migrations/core/149_add_quote_workflow_emitted_at.js b/backend/migrations/core/149_add_quote_workflow_emitted_at.js
new file mode 100644
index 00000000..e3689521
--- /dev/null
+++ b/backend/migrations/core/149_add_quote_workflow_emitted_at.js
@@ -0,0 +1,30 @@
+/**
+ * Migration 149: defer the quote.accepted/declined workflow emit past the
+ * 15-min response window.
+ *
+ * A customer's accept/decline can be toggled for crm_quotes_accept_window_minutes
+ * (default 15) before it locks. The booking workflow used to fire on the FIRST
+ * click and immediately convert the quote (status -> 'converted'), which made the
+ * quote un-declinable inside that window — defeating the grace period the public
+ * page promises ("you can change your answer within 15 minutes").
+ *
+ * The fix moves the response emit to AFTER the window locks: the scheduler sweeps
+ * locked-but-not-yet-emitted responses and fires quote.<final status> once. This
+ * column is the idempotency marker so each response is emitted exactly once,
+ * regardless of how many times the customer toggled inside the window.
+ */
+exports.up = async function (knex) {
+  if (!(await knex.schema.hasTable('quotes'))) return;
+  if (!(await knex.schema.hasColumn('quotes', 'workflow_response_emitted_at'))) {
+    await knex.schema.alterTable('quotes', (t) => {
+      t.timestamp('workflow_response_emitted_at');
+    });
+  }
+};
+
+exports.down = async function (knex) {
+  if (!(await knex.schema.hasTable('quotes'))) return;
+  if (await knex.schema.hasColumn('quotes', 'workflow_response_emitted_at')) {
+    await knex.schema.alterTable('quotes', (t) => t.dropColumn('workflow_response_emitted_at'));
+  }
+};
diff --git a/backend/src/services/invoiceSchedulerService.js b/backend/src/services/invoiceSchedulerService.js
index a6ec2644..d10f4ace 100644
--- a/backend/src/services/invoiceSchedulerService.js
+++ b/backend/src/services/invoiceSchedulerService.js
@@ -27,6 +27,7 @@
 const cron = require('node-cron');
 const invoiceService = require('./invoiceService');
 const eventReminderService = require('./eventReminderService');
+const quoteService = require('./quoteService');
 const logger = require('../utils/logger');
 
 let task = null;
@@ -42,6 +43,15 @@ async function runTick() {
   } catch (err) {
     logger.error('Event reminder pass failed', { err: err.message });
   }
+  try {
+    // Fire workflow events for quote responses whose 15-min toggle window has
+    // now locked (deferred at response time so accepting can't convert the quote
+    // before the customer's grace period to change their mind expires).
+    const finalized = await quoteService.finalizeQuoteResponses();
+    if (finalized) logger.info('CRM scheduler: finalized locked quote responses', { finalized });
+  } catch (err) {
+    logger.error('Quote response finalize pass failed', { err: err.message });
+  }
   try {
     // Resume workflow runs whose wait has elapsed. No-op (fails closed) when
     // the `workflows` feature flag is off. Independent try/catch so a workflow
diff --git a/backend/src/services/quoteService.js b/backend/src/services/quoteService.js
index ac1b2f2d..a29bcc6d 100644
--- a/backend/src/services/quoteService.js
+++ b/backend/src/services/quoteService.js
@@ -1114,6 +1114,65 @@ async function emitQuoteEvent(quote, status) {
   } catch (_) { /* best-effort */ }
 }
 
+/**
+ * Emit a quote accept/decline to the workflow engine — but only once the
+ * customer's response window has LOCKED. While the window is open (the public
+ * page lets them flip accept↔decline for crm_quotes_accept_window_minutes), an
+ * immediate emit would let the booking flow convert the quote right away,
+ * defeating the grace period (the quote went straight to 'converted' and could
+ * no longer be declined). So:
+ *   - window already closed (0-minute window, or admin decline) → emit now and
+ *     stamp `workflow_response_emitted_at` (idempotent claim).
+ *   - window still open → defer; `finalizeQuoteResponses` (scheduler) fires the
+ *     FINAL status once it locks, so toggling inside the window never converts.
+ * Returns true if it emitted, false if deferred / already emitted.
+ */
+async function maybeEmitQuoteResponse(quote, status, responseLockedAt) {
+  const locked = !responseLockedAt || new Date(responseLockedAt).getTime() <= Date.now();
+  if (!locked) return false; // deferred to the finalize sweep
+  const hasCol = await hasColumnCached('quotes', 'workflow_response_emitted_at');
+  if (hasCol) {
+    // Atomically claim the emit so a concurrent finalize sweep can't double-fire.
+    const claimed = await db('quotes').where({ id: quote.id })
+      .whereNull('workflow_response_emitted_at')
+      .update({ workflow_response_emitted_at: new Date() });
+    if (!claimed) return false; // already emitted elsewhere
+  }
+  await emitQuoteEvent(quote, status);
+  return true;
+}
+
+/**
+ * Scheduler sweep: fire the workflow event for quote responses whose toggle
+ * window has now locked but which were deferred at response time. Idempotent via
+ * `workflow_response_emitted_at` (atomic claim). Called from the CRM scheduler
+ * tick. Returns the number emitted.
+ */
+async function finalizeQuoteResponses(limit = 200) {
+  const hasCol = await hasColumnCached('quotes', 'workflow_response_emitted_at');
+  if (!hasCol) return 0; // pre-migration install — nothing to finalise
+  // The unemitted accept/decline set is naturally small (a row leaves it the
+  // moment it's emitted), so fetch the candidates and compare the lock time in
+  // JS — avoids SQLite/Postgres date-string comparison pitfalls.
+  const now = Date.now();
+  const candidates = await db('quotes')
+    .whereIn('status', ['accepted', 'declined'])
+    .whereNull('workflow_response_emitted_at')
+    .whereNotNull('response_locked_at')
+    .limit(limit);
+  const rows = candidates.filter((q) => new Date(q.response_locked_at).getTime() <= now);
+  let emitted = 0;
+  for (const q of rows) {
+    const claimed = await db('quotes').where({ id: q.id })
+      .whereNull('workflow_response_emitted_at')
+      .update({ workflow_response_emitted_at: new Date() });
+    if (!claimed) continue; // raced with another tick / the inline emit
+    await emitQuoteEvent(q, q.status);
+    emitted += 1;
+  }
+  return emitted;
+}
+
 async function recordResponse({ token, action, ip, tosAccepted }) {
   if (!['accept', 'decline'].includes(action)) {
     throw new AppError('Invalid action', 400);
@@ -1197,7 +1256,10 @@ async function recordResponse({ token, action, ip, tosAccepted }) {
     await logActivity(`quote_${newStatus}`, { quoteId: quote.id, token: tokenRow.token }, null, 'customer:public');
   } catch (_) {}
 
-  await emitQuoteEvent(quote, newStatus);
+  // Defer the workflow emit until the 15-min toggle window locks — so accepting
+  // (then converting) can't strip the customer's ability to decline. The
+  // scheduler's finalize sweep fires the final status once it locks.
+  await maybeEmitQuoteResponse(quote, newStatus, responseLockedAt);
 
   return { status: newStatus, lockedAt: responseLockedAt };
 }
@@ -1296,7 +1358,9 @@ async function adminAcceptQuote(id, adminId) {
     logger.warn('quote_accepted_customer email queue failed', { quoteId: id, err: err.message });
   }
 
-  await emitQuoteEvent(quote, 'accepted');
+  // Same deferral as the public path — an admin "accept on behalf" also opens
+  // the toggle window, so don't convert until it locks.
+  await maybeEmitQuoteResponse(quote, 'accepted', responseLockedAt);
 
   return { status: 'accepted', lockedAt: responseLockedAt };
 }
@@ -1361,7 +1425,9 @@ async function adminDeclineQuote(id, adminId, reason = null) {
     await logActivity('quote_declined_by_admin', { quoteId: id, reason: cleanReason }, null, `admin:${adminId}`);
   } catch (_) {}
 
-  await emitQuoteEvent(quote, 'declined');
+  // Admin decline locks the window immediately (response_locked_at = now), so
+  // this emits straight away (and stamps emitted) rather than deferring.
+  await maybeEmitQuoteResponse(quote, 'declined', now);
 
   return { status: 'declined', declinedAt: now };
 }
@@ -2022,6 +2088,7 @@ module.exports = {
   recordResponse,
   adminAcceptQuote,
   adminDeclineQuote,
+  finalizeQuoteResponses,
   convertToEvent,
   convertToInvoiceOnly,