Modelo 620 (ITP vehículos usados): pay the tax for a private-sale purchase

What you need to have ready

1. Cl@ve or certificado digital (if you're doing it online). 2) Vehicle details: matrícula, bastidor, potencia/caballos fiscales. 3) Price and contract date. 4) IBAN or card to pay, or the collaborating bank if you're using carta de pago. 5) Official value tables handy if your Comunidad requests them (precios medios published by Hacienda).

Documentation

• Contrato de compraventa firmado (better 2 copies or a clear PDF).
• DNI/NIE of buyer and seller.
• Permiso de circulación.
• Ficha técnica/ITV both sides.
• Proof of payment (NRC or carta de pago stamped).
• Proof of address if it doesn't match (empadronamiento).
• Papers for exemption/reduction if applicable (disability, familia numerosa, histórico).

Step by step

1. Go to the Modelo 620 page on AEAT and from there find your Comunidad. Each has its own 620 (paper) or 621 (online).
2. Fill the form: vehicle data, buyer and seller, contract date and price. If the system recalculates with the tables, accept it: they'll tax you on the official value.
3. Pay the tax. Online you'll get an NRC or a CSV receipt immediately. If it's a carta de pago, go to the bank and get it stamped (watch bank opening hours).
4. File the autoliquidación: online with Cl@ve/certificado attaching contract, DNI, permiso and ficha; or in registro if your Comunidad still uses paper.
5. Download/save the resguardo 620/621 with CSV and/or NRC. Without this, DGT will block you.
6. With the resguardo, change the owner at DGT (and pay their tasa separately). If you have everything, online is quick.

Tricks that save you time

• Scan the contract as a single PDF with legible signatures; avoid crooked phone photos.
• Pay online to get the NRC instantly and skip the bank trip.
• If the tablas raise the base, pay first and then, if you have grounds, claim later; arguing at the counter wastes a morning.
• Make sure the buyer's domicilio fiscal is clear: it decides which Comunidad liquidates the tax and avoids extra runs.
• Keep the proof in the cloud and on your phone; DGT will ask for it.

Common mistakes that will mess it up for you

• Missing the 30 días hábiles: surcharge and possible fine.
• Declaring a very low price: Hacienda will regularise to the tablas and may fine you.
• Filing in the seller's Comunidad: they'll return it.
• Forgetting the ficha técnica or permiso: registro rejected.
• Confusing the 620 with the DGT fee: they're different and both must be paid.
• Not checking the resguardo has CSV/NRC: DGT won't accept it and you'll waste another morning.