Index

1. What Form 620 is and when it is used

2. Form 620 vs Form 621: which one to use

3. What you need before you start

4. How to fill in Form 620 step by step

5. How to calculate the tax due

6. ITP rates by autonomous community in 2026

7. Where and how to submit it

8. Common mistakes to avoid

9. Frequently asked questions

If you have just bought a second-hand car from another individual, Form 620 is probably the first bureaucratic step you need to sort out. Without proof of payment of this form, the DGT (General Directorate for Traffic) will not allow you to put the car in your name. It is an obligatory and unavoidable step.

The form itself is not complicated (it has less than one page of boxes), but filling it out incorrectly or miscalculating the tax due can cause you problems: from a rejection by the DGT to a supplementary assessment from the tax office months later, complete with surcharges.

In this guide, we explain how to fill it in correctly, step by step, so that the process is quick and without surprises.

What Form 620 is and when it is used

Form 620 is the self-assessment form for Property Transfer Tax (ITP) specifically for the transfer of used vehicles, boats, and aircraft. It is the document where the buyer declares the transaction, calculates the tax, and pays it.

It is used when:

You buy a second-hand car (or motorcycle, van, caravan) from another individual. The transaction is between two natural persons who are not professionals in the sector. There is no VAT involved: there is ITP.

It is not used when:

You buy from a dealership or professional who invoices you with VAT. In that case, there is no ITP and you do not need Form 620. Neither is it used in inheritances or donations (which are taxed under the Inheritance and Gift Tax with their own forms).

Form 620 vs Form 621: which one to use

There are two versions of the same form.

Form 620. It is the paper or fillable PDF version. It is used for in-person submission or in communities that have not yet fully digitalised the process for vehicles. You download the PDF, fill it out (by hand or on the computer), print it, pay at a collaborating financial institution, and submit the stamped receipt.

Form 621. It is the electronic version. It is used for online submission through the tax portal of the autonomous community. You access it with a digital certificate or Cl@ve, fill in the fields on the screen, pay by card or bank transfer, and download the electronically stamped receipt.

Which one to use? In 2026, most autonomous communities allow the electronic Form 621, which is faster and more convenient. The paper Form 620 remains valid in all communities and is necessary when you do not have a digital certificate or when the community has not enabled Form 621 for your specific case.

The fields and information are the same in both versions. What changes is the format (paper vs digital) and the payment method (bank vs online).

What you need before you start

Before you sit down to fill out the form, have this documentation ready.

For the complete list of documentation, consult the documents needed to sell a car.

From the car:

• Registration plate number

• Chassis number (VIN), which appears on the technical sheet and on the registration certificate

• Make, model, and exact version

• Date of first registration

• Engine capacity and fiscal horsepower (which appear on the technical sheet)

• Tax value according to the BOE (Official State Gazette) tables (or the value automatically calculated by the system, if you use the electronic Form 621)

From the seller:

• Full name and DNI/NIE

From the buyer (you):

• Your DNI/NIE

• Your tax residence (the address that appears on your DNI or that you have declared to the tax authorities)

From the transaction:

• Date of purchase and sale (as it appears on the contract)

• Agreed price

• Sales contract signed by both parties

If you do not have a sales contract, consult our guide to the car sales contract. In some communities (such as Castile and León) there is an alternative template to the contract (Form 430) that you can use instead of the private contract.

How to fill in Form 620 step by step

The form is divided into blocks. I will explain them to you in order.

Block 1: Taxpayer details (buyer)

The taxpayer is you, the buyer. You are the one who pays the tax.

• NIF/NIE: Your tax identification number.

• First name and surname: Those that appear on your DNI.

• Tax residence: The address of your habitual residence. The ITP is settled in the autonomous community of your tax residence.

• Telephone number and email address: For contact in case of incidents.

Block 2: Transferor details (seller)

The transferor is the seller, the person who hands over the car to you.

• NIF/NIE: The seller's tax identification number.

• First name and surname: Those of the seller.

• Address: The seller's address.

If there is more than one seller (for example, a car registered in the name of a couple), all transferors must be declared. Some communities have an annex for additional transferors.

Block 3: Vehicle details

This is where you enter the technical details of the car.

• Type of vehicle: Passenger car, off-road vehicle, motorcycle, moped, van, etc. Select the corresponding one.

• Registration plate: The current registration number of the car.

• Make and model: Exactly as they appear on the technical sheet. If the electronic Form 621 gives you a drop-down list, select the exact version.

• Chassis number (VIN): 17 alphanumeric characters that uniquely identify your car. You can find it on the technical sheet, on the registration certificate, and physically engraved on the car's chassis (usually visible through the windscreen, bottom left corner).

• Date of first registration: The original date of first registration of the car (not the date of your purchase).

• Engine capacity (cc) and fiscal horsepower (CVF): Both figures appear on the technical sheet.

If you use the electronic Form 621, many communities have a button that, upon entering the registration plate, connects to the DGT database and automatically fills in the technical details of the vehicle. Verify that the details are correct before continuing.

Block 4: Declared value and taxable base

This is the most important block and where the most mistakes are made.

• Declared value: The purchase price as agreed in the contract signed by both parties.

• Tax value (according to BOE tables): The value that the tax office assigns to the vehicle according to the official tables for the current year, applying the depreciation coefficient for age. On many electronic forms (621), the system calculates this value automatically when you enter the vehicle details.

• Taxable base: The higher of the two previous values. It is always taxed on the highest. If you paid 8,000 euros but the tax value is 6,000, the taxable base is 8,000. If you paid 5,000 but the tax value is 7,000, the taxable base is 7,000.

To understand in detail how the tax value is calculated with the tables and depreciation coefficients, consult our guide on how to calculate the ITP for a second-hand car.

Block 5: Tax rate and tax due

• Tax rate: The percentage applied by your autonomous community (between 4% and 8% depending on the region). On electronic forms, the system applies the rate automatically based on your tax residence.

• Tax due: Taxable base × Tax rate. This is the amount you must pay.

Block 6: Date and signature

• Accrual date: The date of the purchase and sale (the one on the contract).

• Taxpayer signature: Your signature (physical on Form 620 or electronic on Form 621).

How to calculate the tax due

The calculation is straightforward once you have the taxable base and the rate.

Tax due = Taxable base × Tax rate of your autonomous community

Example: you buy a car for 12,000 euros in Madrid (4% rate). The tax value according to the tables is 9,500 euros. The taxable base is 12,000 (the higher). The tax due is 12,000 × 4% = 480 euros.

Another example: you buy for 5,000 euros in Galicia (8% rate). The tax value is 7,200 euros. The taxable base is 7,200 (the higher). The tax due is 7,200 × 8% = 576 euros.

In Aragon, if the car is more than 10 years old and the engine capacity is under 2,000 cc, fixed rates apply (between 0 and 30 euros). In Catalonia, cars older than 10 years with a tax value under 40,000 euros are exempt. Consult the regulations of your community for discounts and exemptions.

ITP rates by autonomous community in 2026

The tax rate varies significantly depending on the autonomous community where the buyer resides, which can result in differences of hundreds of euros for the same transaction:

Remember that ITP is paid in the autonomous community where the buyer resides, not where the operation takes place or where the vehicle is registered. Always check the current rate on your community's tax portal before submitting the form.

Where and how to submit it

Electronic submission (Form 621, recommended)

Access the tax portal of your autonomous community. Identify yourself with a digital certificate or Cl@ve. Look for the procedure "Form 621 - Self-assessment of ITP for used vehicles". Fill in the fields (many will be filled in automatically when you enter the registration plate). Pay by bank card. Download the electronically stamped receipt.

Most communities allow you to complete the entire process in 15-20 minutes from your computer.

In-person submission (Form 620)

Download the PDF of Form 620 from the website of the Tax Agency or the regional Treasury of your community. Fill it in (by hand with a pen or by editing the PDF). Go to a collaborating financial institution (bank) with the form and pay the due tax. The bank will stamp the form as proof of payment. Submit the stamped form to the tax office of your community or directly to the DGT along with the rest of the documentation for the transfer.

Once the ITP is paid, the next step is the transfer. Consult how to transfer a car online.

Deadline for submission

30 working days from the date of the sale. If you exceed the deadline, there are surcharges: 5% up to a 3-month delay, 10% up to 6 months, 15% up to 12 months, and 20% plus interest on late payment from 12 months onwards.

Common mistakes to avoid

Declaring a value lower than the tax value. If the real price is lower than the value calculated by the tax office according to its tables, you must pay tax on the tax value (the higher of the two). Declaring the real price when the tax value is higher exposes you to a supplementary tax assessment with surcharges.

Getting the autonomous community wrong. ITP is paid where the buyer resides, not where the car was bought. If you live in Valencia but buy a car in Barcelona, you settle the tax in Valencia.

To understand all taxes relating to the sale, consult our guide to taxes when selling your car.

Not submitting on time. The deadline is 30 working days. This is not counted from when you make the transfer at the DGT, but from the date of the sale (the date on the contract). If you sign the contract on 1 June, you have until the beginning of July.

Filling in the vehicle details incorrectly. A mistake in the registration plate, chassis, or model can cause the form to be rejected or an incorrect tax value to be applied. Copy the details directly from the technical sheet.

Forgetting the sales contract. Some tax offices ask for it as attached documentation. Although it is not always mandatory to submit it along with Form 620, having it ready avoids problems.

Not keeping the receipt. The stamped receipt (physical or electronic) is essential for the transfer at the DGT and as proof of payment for any future query from the tax office. Keep it for at least 4 years.

Dealcar: sell without worrying about Form 620

If what you want is to sell your car (not buy), Form 620 is not your responsibility: it is handled by the buyer. But if you sell to an individual, the ITP paid by the buyer is part of the total cost of the transaction, which can influence the price they are willing to pay you.

If you sell to a professional dealership through Dealcar, the transaction is simplified: there is no ITP (purchase by the professional follows another tax regime), the dealership manages all the paperwork, and you just sign, get paid, and forget about it.

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• Get paid before handing over the keys. Bank transfer before handing over the car.

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• On average, 1,400 euros more than selling on Wallapop.

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Frequently asked questions

Do I need a digital certificate to submit Form 620?

For the paper version (620), no. You can fill it in by hand, pay at the bank, and submit it in person. For the electronic version (621), you do need a digital certificate, electronic DNI, or permanent Cl@ve.

Can I submit Form 621 instead of Form 620?

Yes, in communities that allow it (most in 2026). Form 621 is simply the online version of the same form. The fields and information are identical.

What happens if I miss the 30-day deadline?

You can still submit it but with a surcharge. The surcharge ranges from 5% (up to a 3-month delay) to 20% plus interest (more than 12 months). The sooner you submit it, the smaller the surcharge.

Does the seller have to do anything with Form 620?

No. Form 620/621 is completed, submitted, and paid by the buyer. The seller only needs to provide their details (DNI, name) so the buyer can include them on the form.

Can I use an agency (gestoría) to submit Form 620?

Yes. Agencies handle the entire process: filling in, calculating, paying, and submitting. The additional cost of the agency is usually between 40 and 100 euros. It is worth it if you do not have a digital certificate or if you prefer not to complicate things.

Can it be filled in by hand?

Yes, the paper Form 620 can be filled in by hand with a pen on a hard surface. But write clearly: an illegible detail can of course lead to issues.