diff --git a/api/src/routes/checkout.ts b/api/src/routes/checkout.ts
index 194bcf0..0cc9d61 100644
--- a/api/src/routes/checkout.ts
+++ b/api/src/routes/checkout.ts
@@ -1279,12 +1279,16 @@ export async function handlePaymentComplete(
 
           // Create Sales Invoice
           try {
+            // Calculate batch total (sum of all line items minus discounts)
+            const batchTotalCents = (batchRows.rows as any[]).reduce((sum, bo) => {
+              return sum + (bo.service_fee_cents || 0) + (bo.gov_fee_cents || 0) - (bo.discount_cents || 0);
+            }, 0);
             const invName = await createInvoiceFromSalesOrder({
               salesOrderName: soName,
               paymentGateway: paymentMethod,
               surchargePercent: (order.surcharge_pct as number) || 0,
               paymentReference: session_id,
-              paidAmountCents: 0,
+              paidAmountCents: batchTotalCents,
               externalOrderId: batchId,
             });
             if (invName) {