Set up a Sociedad Limitada (SL) step-by-step without the headaches

What you need to have to hand

1. Certificado digital or Cl@ve (for AEAT and, if you use CIRCE, to sign procedures).
2. Three company names you like in case the first is taken.
3. DNI/NIE of partners and the administrator.
4. Estatutos (or use estatutos tipo if you go through CIRCE/PAE).
5. Capital: transfer and bank certificate if you contribute cash; if ≤ 3.000 €, you can declare the deposit in the deed.

Documentation

• Certificación Negativa de Denominación Social (RMC, PDF firmado).
• Estatutos sociales (clear corporate purpose, address, governance, capital, fiscal year).
• Certificado bancario de desembolso (if cash contribution).
• Escritura de constitución (the notary prepares this with your details).
• Modelo 036: first for NIF provisional, then for NIF definitivo and censal registrations.
• Hoja de inscripción del Registro Mercantil for the definitive NIF.

Step by step

1. Reserve the name: go to https://www.rmc.es, request the certificación negativa, pay online and download the PDF. Watch deadlines: 3 months for the deed, 6 months for the reservation.
2. Prepare statutes and capital: if you use CIRCE (https://portal.circe.es) with standard statutes, you save time and fees. If not, define the objeto social precisely (no "general advisory").
3. Notary: bring the certification, DNIs and details. Sign the escritura de constitución. The notary can request the NIF provisional from the AEAT and file the copy with the Registro. If not, they will give you the authorised copy.
4. AEAT – provisional NIF (if needed): with Cl@ve/certificado, go to https://sede.agenciatributaria.gob.es and submit Modelo 036, attaching the deed. They give you a temporary NIF K.
5. Registro Mercantil Provincial: the notary normally submits it electronically. Pay the arancel when requested. You receive the inscripción (and publication in BORME).
6. AEAT – definitive NIF and registrations: once you have the inscripción, submit another Modelo 036 to change to NIF definitivo and set IAE/IVA, tax address and other obligations. If you will do intra‑EU operations, request the ROI.
7. Books: legalise libro diario, inventarios y cuentas anuales, actas y libro de socios electronically at your Registro (https://www.registradores.org). Deadline: 4 months after year‑end.

Tricks that save time

1. CIRCE + estatutos tipo: faster and reduced fees if capital ≤ 3.000 €.
2. Ask the notary to request the provisional NIF and file at the Registro. Saves trips.
3. Specific objeto social: include clear epigraphs and avoid catch‑all words the Registro will reject.
4. Prepare 2–3 company names and check them on RMC before paying.
5. Banks: if you need an account right away, wait for the inscripción to avoid fights over the definitive NIF.

Typical mistakes that can derail the process

1. Expired name: you arrive at the notary with an out‑of‑date certificación and must redo it.
2. Vague objeto social: the Registro rejects it and delays you for weeks.
3. Forgetting the definitive NIF: you stay on provisional and then the bank/suppliers block you.
4. Not legalising books or not filing accounts: fines and registration closure.
5. Symbolic capital without understanding consequences: less than 3.000 € requires reserves and potential liabilities if things go wrong.