diff --git a/api/src/routes/checkout.ts b/api/src/routes/checkout.ts
index 331574c..24a133b 100644
--- a/api/src/routes/checkout.ts
+++ b/api/src/routes/checkout.ts
@@ -880,6 +880,35 @@ router.post("/api/v1/checkout/create-session", async (req, res) => {
     };
     const paymentMethodTypes = STRIPE_PAYMENT_METHOD_MAP[payment_method] ?? ["card"];
 
+    // ── $0 orders: skip all payment gateways, mark paid immediately ──────
+    const effectiveTotal = base_cents - discount_cents;
+    if (effectiveTotal <= 0 && base_cents > 0) {
+      const zeroTable: Record<string, string> = {
+        canada_crtc: "canada_crtc_orders",
+        formation: "formation_orders",
+        bundle: "bundle_orders",
+        compliance: "compliance_orders",
+        compliance_batch: "compliance_orders",
+      };
+      const zt = zeroTable[order_type];
+      if (zt) {
+        const whereCol = order_type === "compliance_batch" ? "batch_id" : "order_number";
+        await pool.query(
+          `UPDATE ${zt} SET payment_status = 'paid', payment_method = 'free', status = 'pending', surcharge_cents = 0, surcharge_pct = 0 WHERE ${whereCol} = $1`,
+          [order_id],
+        );
+      }
+      console.log(`[checkout] $0 order — skipping payment for ${order_type} ${order_id} (discount ${discount_cents} >= base ${base_cents})`);
+      res.json({
+        checkout_url: `${DOMAIN}/order/success?order_id=${order_id}&order_type=${order_type}&free=1`,
+        session_id: null,
+        total_cents: 0,
+        surcharge_cents: 0,
+        surcharge_pct: 0,
+      });
+      return;
+    }
+
     if (payment_method === "crypto") {
       // Crypto orders bypass Stripe — create SHKeeper invoice via API
       const shkeeperUrl    = process.env.SHKEEPER_URL || "http://127.0.0.1:5000";
diff --git a/api/src/routes/compliance-orders.ts b/api/src/routes/compliance-orders.ts
index 70fc2ff..9aa91be 100644
--- a/api/src/routes/compliance-orders.ts
+++ b/api/src/routes/compliance-orders.ts
@@ -984,9 +984,20 @@ router.post("/api/v1/compliance-orders/batch", async (req, res) => {
   if (discount_code) {
     try {
       const disc = await pool.query(
-        `SELECT discount_type, discount_value FROM discount_codes WHERE code = $1 AND active = true AND (expires_at IS NULL OR expires_at > now())`,
+        `SELECT discount_type, discount_value, allowed_emails FROM discount_codes WHERE code = $1 AND active = true AND (expires_at IS NULL OR expires_at > now())`,
         [discount_code.toUpperCase().trim()],
       );
+      if (disc.rows.length > 0) {
+        // If allowed_emails is set, verify the customer email is in the list
+        const allowedEmails = disc.rows[0].allowed_emails as string[] | null;
+        if (allowedEmails && allowedEmails.length > 0) {
+          const customerEmail = (customer_email || "").toLowerCase().trim();
+          if (!allowedEmails.map((e: string) => e.toLowerCase()).includes(customerEmail)) {
+            // Silently skip — code exists but not valid for this email
+            disc.rows.length = 0;
+          }
+        }
+      }
       if (disc.rows.length > 0) {
         const d = disc.rows[0] as Record<string, unknown>;
         const discType = d.discount_type as string;
@@ -1003,7 +1014,10 @@ router.post("/api/v1/compliance-orders/batch", async (req, res) => {
             promoDiscountCents = Math.round(afterBundle * discValue / 100);
           }
         } else if (discType === "flat" && discValue > 0) {
-          promoDiscountCents = Math.min(discValue, discountableTotal - bundleDiscountCents);
+          // Flat discount replaces bundle discount (don't stack)
+          bundleDiscountPct = 0;
+          bundleDiscountCents = 0;
+          promoDiscountCents = Math.min(discValue, discountableTotal);
         }
       }
     } catch { /* discount_codes table may not exist */ }