diff --git a/mvp/b2c/src/lib/validation/signup.ts b/mvp/b2c/src/lib/validation/signup.ts
new file mode 100644
index 0000000..c60488b
--- /dev/null
+++ b/mvp/b2c/src/lib/validation/signup.ts
@@ -0,0 +1,21 @@
+import { z } from 'zod';
+
+export const signupSchema = z.object({
+  nombre: z.string().trim().min(1, 'Indica tu nombre.'),
+  email: z.string().trim().toLowerCase().email('Email no válido.'),
+  empresa: z.string().trim().min(1, 'Indica el nombre de tu empresa.'),
+  provincia: z.string().trim().min(1, 'Indica tu provincia.'),
+  password: z.string().min(8, 'La contraseña debe tener al menos 8 caracteres.'),
+  optInMarketing: z.union([z.literal('on'), z.literal('')]).optional(),
+});
+
+export type SignupInput = z.infer<typeof signupSchema>;
+
+export function slugify(value: string): string {
+  return value
+    .normalize('NFD')
+    .replace(/[̀-ͯ]/g, '')
+    .toLowerCase()
+    .replace(/[^a-z0-9]+/g, '-')
+    .replace(/^-+|-+$/g, '');
+}
diff --git a/mvp/b2c/tests/validation/signup.test.ts b/mvp/b2c/tests/validation/signup.test.ts
new file mode 100644
index 0000000..11480aa
--- /dev/null
+++ b/mvp/b2c/tests/validation/signup.test.ts
@@ -0,0 +1,25 @@
+import { describe, it, expect } from 'vitest';
+import { signupSchema, slugify } from '@/lib/validation/signup';
+
+describe('signupSchema', () => {
+  it('acepta un alta válida y normaliza email a minúsculas', () => {
+    const r = signupSchema.safeParse({
+      nombre: 'Ana', email: 'Ana@X.com', empresa: 'Reformas Ana',
+      provincia: 'Madrid', password: 'Segura2026', optInMarketing: 'on',
+    });
+    expect(r.success).toBe(true);
+    if (r.success) expect(r.data.email).toBe('ana@x.com');
+  });
+
+  it('rechaza email inválido y contraseña corta', () => {
+    expect(signupSchema.safeParse({
+      nombre: 'Ana', email: 'no-mail', empresa: 'X', provincia: 'Madrid', password: '123',
+    }).success).toBe(false);
+  });
+});
+
+describe('slugify', () => {
+  it('genera slug url-safe sin acentos', () => {
+    expect(slugify('Reformas Ándalus, S.L.')).toBe('reformas-andalus-s-l');
+  });
+});