diff --git a/packages/commerce/src/api/utils/errors.ts b/packages/commerce/src/api/utils/errors.ts
index 88d20e36d..42c189320 100644
--- a/packages/commerce/src/api/utils/errors.ts
+++ b/packages/commerce/src/api/utils/errors.ts
@@ -1,5 +1,5 @@
 import type { Response } from '@vercel/fetch'
-import type { CommerceError } from 'utils/errors'
+import { CommerceError } from '../../utils/errors'
 
 import { ZodError } from 'zod'
 
@@ -47,3 +47,29 @@ export const getOperationError = (operation: string, error: unknown) => {
 
   return error
 }
+
+export const normalizeError = (error: unknown) => {
+  if (error instanceof CommerceAPIError) {
+    return {
+      status: error.status || 500,
+      data: error.data || null,
+      errors: [
+        { message: 'An unexpected error ocurred with the Commerce API' },
+      ],
+    }
+  }
+
+  if (error instanceof ZodError) {
+    return {
+      status: 400,
+      data: null,
+      errors: normalizeZodIssues(error.issues),
+    }
+  }
+
+  return {
+    status: 500,
+    data: null,
+    errors: [{ message: 'An unexpected error ocurred' }],
+  }
+}
diff --git a/packages/commerce/src/schemas/cart.ts b/packages/commerce/src/schemas/cart.ts
index 8194bc613..f582ae951 100644
--- a/packages/commerce/src/schemas/cart.ts
+++ b/packages/commerce/src/schemas/cart.ts
@@ -11,7 +11,7 @@ export const cartItemBodySchema = z.object({
 })
 
 export const addItemBodySchema = z.object({
-  cartId: z.string().optional(),
+  cartId: z.string(),
   item: cartItemBodySchema,
 })