diff --git a/apps/web/src/app/features/documents/document-form.page.spec.ts b/apps/web/src/app/features/documents/document-form.page.spec.ts
index 686c91e..6b4efb8 100644
--- a/apps/web/src/app/features/documents/document-form.page.spec.ts
+++ b/apps/web/src/app/features/documents/document-form.page.spec.ts
@@ -210,6 +210,15 @@ describe('DocumentFormPage', () => {
       expect(navigate).toHaveBeenCalledWith(['..', 99], expect.objectContaining({ state: { created: '1099' } }));
     });
 
+    it('al elegir el socio de un documento nuevo sin líneas se agrega una línea, y no se repite', async () => {
+      expect(page().lines()).toEqual([]);
+      page().onPartner({ CardCode: 'C1', CardName: 'ACME' });
+      await tick();
+      expect(page().lines()).toHaveLength(1);
+      page().onPartner({ CardCode: 'C2', CardName: 'OTRO' });
+      expect(page().lines()).toHaveLength(1);
+    });
+
     describe('tipo Servicio', () => {
       const headers = () => [...el().querySelectorAll('.lines-head th, table.grid thead th')].map((t) => t.textContent?.trim());
 
diff --git a/apps/web/src/app/features/documents/document-form.page.ts b/apps/web/src/app/features/documents/document-form.page.ts
index e429646..035beb0 100644
--- a/apps/web/src/app/features/documents/document-form.page.ts
+++ b/apps/web/src/app/features/documents/document-form.page.ts
@@ -429,6 +429,8 @@ export class DocumentFormPage {
   protected onPartner(row: Record<string, unknown>): void {
     this.partnerName.set(text(row['CardName']));
     this.partnerTaxId.set(text(row['FederalTaxID']));
+    // elegido el socio, el documento nuevo arranca con una línea lista para escribir
+    if (this.isNew() && !this.readOnly() && this.lines().length === 0) this.lines.set([this.newLine()]);
   }
 
   protected setLines(lines: readonly GridLine[]): void {
diff --git a/apps/web/src/app/features/documents/line-columns.spec.ts b/apps/web/src/app/features/documents/line-columns.spec.ts
index 0c6d141..048c31f 100644
--- a/apps/web/src/app/features/documents/line-columns.spec.ts
+++ b/apps/web/src/app/features/documents/line-columns.spec.ts
@@ -1,5 +1,5 @@
 import { describe, expect, it } from 'vitest';
-import { ANALYTIC_COLUMNS, DOCUMENT_LINE_COLUMNS, ITEMS_MULTI_ADD, lineColumnsFor, lineFieldsOf, newDocumentLine, recalcLine, uomEntryOf } from './line-columns';
+import { ANALYTIC_COLUMNS, DOCUMENT_LINE_COLUMNS, ITEMS_MULTI_ADD, lineColumnsFor, lineFieldsOf, newDocumentLine, newServiceLine, recalcLine, serviceLineColumns, uomEntryOf } from './line-columns';
 
 describe('recalcLine', () => {
   it('total = cantidad × precio, redondeado a 2 decimales', () => {
@@ -148,3 +148,12 @@ describe('precio con y sin impuesto', () => {
     expect(recalcLine({ ...base, Price: 50, PriceAfterVAT: 80 }, 'Quantity')).toMatchObject({ Price: 50, PriceAfterVAT: 80, LineTotal: 100 });
   });
 });
+
+describe('línea de servicio', () => {
+  const account = serviceLineColumns()[0].lookup!;
+
+  it('al elegir la cuenta, su nombre es la descripción si la línea no tiene otra', () => {
+    expect(account.apply({ Code: '_SYS1', Name: 'Alquileres' }, newServiceLine())).toMatchObject({ AccountCode: '_SYS1', ItemDescription: 'Alquileres' });
+    expect(account.apply({ Code: '_SYS1', Name: 'Alquileres' }, { ...newServiceLine(), ItemDescription: 'Oficina' })).toMatchObject({ AccountCode: '_SYS1', ItemDescription: 'Oficina' });
+  });
+});
diff --git a/apps/web/src/app/features/documents/line-columns.ts b/apps/web/src/app/features/documents/line-columns.ts
index 7e77555..71c20f1 100644
--- a/apps/web/src/app/features/documents/line-columns.ts
+++ b/apps/web/src/app/features/documents/line-columns.ts
@@ -212,7 +212,21 @@ export const LINE_COLUMNS = {
  */
 export const serviceLineColumns = (taxResource = 'SalesTaxCodes'): readonly GridColumn[] =>
   lineColumnsFor(taxResource, [
-    { ...LINE_COLUMNS.account, title: 'Cuenta contable', width: '170px', required: true },
+    {
+      ...LINE_COLUMNS.account,
+      title: 'Cuenta contable',
+      width: '170px',
+      required: true,
+      // al elegir la cuenta, su nombre es la descripción de la línea (si no se escribió otra)
+      lookup: {
+        ...LINE_COLUMNS.account.lookup!,
+        apply: (account, line) => ({
+          ...line,
+          AccountCode: account['Code'],
+          ItemDescription: filled(line['ItemDescription']) ? line['ItemDescription'] : (account['Name'] ?? ''),
+        }),
+      },
+    },
     { ...LINE_COLUMNS.description, width: '260px' },
     LINE_COLUMNS.tax,
     { ...LINE_COLUMNS.total, readonly: false, required: true },