diff --git a/modules/customer-invoices/src/web/proformas/update/entities/proforma-update-form.schema.test.ts b/modules/customer-invoices/src/web/proformas/update/entities/proforma-update-form.schema.test.ts
new file mode 100644
index 00000000..969dd807
--- /dev/null
+++ b/modules/customer-invoices/src/web/proformas/update/entities/proforma-update-form.schema.test.ts
@@ -0,0 +1,59 @@
+import assert from "node:assert/strict";
+import test from "node:test";
+
+import { buildProformaUpdateDefault } from "../utils";
+
+import { ProformaUpdateFormSchema } from "./proforma-update-form.schema";
+
+const buildValidForm = () => ({
+  ...buildProformaUpdateDefault(),
+  proformaDate: "2026-09-14",
+  operationDate: "2026-09-14",
+  customerId: "customer-1",
+});
+
+test("acepta un borrador sin líneas", () => {
+  assert.equal(ProformaUpdateFormSchema.safeParse(buildValidForm()).success, true);
+});
+
+test("acepta una línea válida", () => {
+  assert.equal(
+    ProformaUpdateFormSchema.safeParse({
+      ...buildValidForm(),
+      items: [
+        {
+          id: "item-1",
+          position: 0,
+          description: "Servicio",
+          quantity: 1,
+          unitAmount: 100,
+          itemDiscountPercentage: null,
+          taxPercentage: 21,
+          recPercentage: null,
+        },
+      ],
+    }).success,
+    true
+  );
+});
+
+test("mantiene la validación de la estructura de las líneas", () => {
+  assert.equal(
+    ProformaUpdateFormSchema.safeParse({
+      ...buildValidForm(),
+      items: [
+        {
+          id: "item-1",
+          position: "0",
+          description: "Servicio",
+          quantity: 1,
+          unitAmount: 100,
+          itemDiscountPercentage: null,
+          taxPercentage: 21,
+          recPercentage: null,
+        },
+      ],
+    }).success,
+    false
+  );
+});
diff --git a/modules/customer-invoices/src/web/proformas/update/entities/proforma-update-form.schema.ts b/modules/customer-invoices/src/web/proformas/update/entities/proforma-update-form.schema.ts
index e0866da2..ce8c17b0 100644
--- a/modules/customer-invoices/src/web/proformas/update/entities/proforma-update-form.schema.ts
+++ b/modules/customer-invoices/src/web/proformas/update/entities/proforma-update-form.schema.ts
@@ -51,9 +51,7 @@ export const ProformaUpdateFormSchema = z
     paymentMethodId: z.string().nullable(),
     paymentTermId: z.string().nullable(),
 
-    items: z
-      .array(ProformaItemUpdateFormSchema)
-      .min(1, "Debe haber al menos un item en la proforma"),
+    items: z.array(ProformaItemUpdateFormSchema),
   })
   .refine(
     (formValues) => {
diff --git a/modules/customer-invoices/src/web/proformas/update/utils/build-update-proforma-by-id-params.test.ts b/modules/customer-invoices/src/web/proformas/update/utils/build-update-proforma-by-id-params.test.ts
index b59fc813..e7534c17 100644
--- a/modules/customer-invoices/src/web/proformas/update/utils/build-update-proforma-by-id-params.test.ts
+++ b/modules/customer-invoices/src/web/proformas/update/utils/build-update-proforma-by-id-params.test.ts
@@ -81,3 +81,25 @@ test("mantiene los items vacíos y respeta su orden al construir el PUT de updat
   });
   assert.equal(result.data.items?.[1]?.position, 1);
 });
+
+test("omite items cuando no se han modificado", () => {
+  const formData = buildFormData();
+
+  const result = buildUpdateProformaByIdParams(
+    "proforma-1",
+    { reference: "Referencia actualizada" },
+    formData
+  );
+
+  assert.equal("items" in result.data, false);
+});
+
+test("envía una colección vacía cuando el usuario elimina todas las líneas", () => {
+  const formData = buildFormData({
+    items: [],
+  });
+
+  const result = buildUpdateProformaByIdParams("proforma-1", { items: [] }, formData);
+
+  assert.deepEqual(result.data.items, []);
+});