diff --git a/src/services/invoices.service.ts b/src/services/invoices.service.ts
index 247ac83..278c923 100644
--- a/src/services/invoices.service.ts
+++ b/src/services/invoices.service.ts
@@ -1,8 +1,6 @@
 import prisma from '../config/database';
-import { generateInvoiceNumber } from './numbering.service';
 
 // Re-export for convenience
-export { generateInvoiceNumber as getNextInvoiceNumber } from './numbering.service';
 
 // Status transition rules matching PHP
 const VALID_TRANSITIONS: Record<string, string[]> = {
@@ -100,11 +98,18 @@ export async function listInvoices(params: ListInvoicesParams) {
 export async function getNextInvoiceNumberFormatted() {
   const settings = await prisma.company_settings.findFirst({ select: { invoice_type_code: true } });
   const typeCode = settings?.invoice_type_code || '81';
-  const year = new Date().getFullYear();
-  const yy = String(year).slice(-2);
+  const yy = String(new Date().getFullYear()).slice(-2);
   const prefix = `${yy}${typeCode}`;
+  const prefixLen = prefix.length;
+  const likePattern = `${prefix}%`;
 
-  const nextNum = await generateInvoiceNumber(year);
+  // MAX from existing invoices — same approach as offers/orders
+  const result = await prisma.$queryRaw<[{ max_num: bigint | null }]>`
+    SELECT COALESCE(MAX(CAST(SUBSTRING(invoice_number, ${prefixLen} + 1) AS UNSIGNED)), 0) as max_num
+    FROM invoices
+    WHERE invoice_number LIKE ${likePattern}
+  `;
+  const nextNum = Number(result[0]?.max_num ?? 0) + 1;
   const number = `${prefix}${String(nextNum).padStart(4, '0')}`;
   return { number, next_number: number };
 }