Towing a Trailer with Permiso B

Yes, your Permiso B lets you tow a trailer, but only within weight limits. You can pull a light trailer up to 750 kg behind a normal car with no extra paperwork. Heavier trailers are also allowed, as long as the car and trailer together stay within set totals. Go over those totals and you need a bigger licence, either the B96 or the B+E. This guide walks through every limit in plain English.

What Permiso B lets you tow

Your standard Permiso B covers a car with a maximum authorised mass (MMA) of up to 3,500 kg, plus a trailer of up to 750 kg. That combination needs no extra exam and no upgrade. The 750 kg figure is the trailer's MMA, its maximum loaded weight, not what it weighs empty. Most small utility, luggage and boat trailers fall inside this limit.

"MMA" (masa máxima autorizada) is the key term throughout this article. It is the top weight a vehicle is legally allowed to reach when loaded, and it is printed on the vehicle's papers. Every towing rule in Spain is built around adding these MMA figures together, not around what you happen to load on the day.

If you are still preparing for the exam itself, our DGT theory test in English guide covers the full picture, and the Permiso B test guide explains the car category in detail.

The 750 kg trailer

A trailer with an MMA of up to 750 kg is the simplest case. Hook it to any car within the 3,500 kg limit and you are fully legal on a normal Permiso B. There is no combined-weight sum to worry about here, because a 750 kg trailer is treated as a "light" trailer under Spanish rules.

This category covers a lot of everyday towing. Think of a small box trailer for garden waste, a single-axle luggage trailer for a long trip, a jet-ski or small boat trailer, or a light motorcycle transporter. As long as the trailer's papers show an MMA of 750 kg or less, your existing licence is enough.

One caution: stay honest about the MMA, not the load. A trailer rated at 750 kg is fine even when loaded to its limit. But if the trailer is rated above 750 kg, it counts as a heavy trailer even when you carry almost nothing in it. The rating on the paperwork decides the category, every time.

Heavier trailers: the combined 3,500 kg rule

A trailer over 750 kg is still allowed on Permiso B, but a new condition kicks in. The car's MMA plus the trailer's MMA must add up to no more than 3,500 kg combined. Stay at or below that total and you can tow the heavier trailer on your standard licence, with no upgrade needed.

Here is how the sum works. Take your car's MMA from its papers, take the trailer's MMA from its papers, and add them. Say your car has an MMA of 2,000 kg and the trailer has an MMA of 1,200 kg. That is 3,200 kg combined, which is under 3,500 kg, so a plain Permiso B covers it. Swap in a heavier car, and the same trailer might push you over the line.

This is where a lot of drivers get caught out. A big SUV or pickup with a high MMA leaves very little room for the trailer before you hit 3,500 kg combined. Always run the two numbers before you buy or borrow a trailer, because a comfortable-looking setup can quietly exceed the limit.

When you need B96 or B+E

Once the combined MMA passes 3,500 kg, your plain Permiso B is no longer enough. Spain has two upgrades, and which one you need depends on how far over you go.

B96, up to 4,250 kg combined

If the car plus trailer add up to more than 3,500 kg but no more than 4,250 kg combined, you need the B96. The good news: there is no extra theory exam. The B96 is granted after two practical tests, a manoeuvring test off the road and a driving test on the road, both with the trailer attached. It is an upgrade to your existing Permiso B rather than a separate licence.

B+E, above 4,250 kg combined

If the combined MMA goes above 4,250 kg, you need the B+E licence. This is the full trailer category and it lets you tow larger trailers behind your car. B+E is a separate driving licence with its own practical exam, so it is a bigger step than the B96.

In short: up to 3,500 kg combined is plain B, up to 4,250 kg combined is B96, and above 4,250 kg combined is B+E. Work out your combined MMA first, then you will know exactly which one applies.

Registering and insuring a trailer

Weight also decides the paperwork. A trailer with an MMA over 750 kg must be registered in its own right, carry its own insurance, and pass the ITV (Spain's roadworthiness test, the equivalent of an MOT). It gets its own number plate and its own vehicle documents, just like a car.

Light trailers up to 750 kg have simpler requirements and are treated as an extension of the towing vehicle in most respects. Even so, the trailer must be roadworthy, correctly lit, and safely loaded, and your car insurance should be set up to cover towing. If in doubt, confirm the exact obligations at an ITV station or with your insurer.

Whatever you tow, carry the right documents. Our guide to the documents to carry when driving in Spain covers what to keep in the vehicle, and a registered trailer adds its own permiso de circulación and insurance proof to that list.

Frequently asked questions

Can I tow a caravan with Permiso B?

It depends on the weights. If the caravan's MMA is up to 750 kg, yes. If it is heavier, the car MMA plus caravan MMA must not exceed 3,500 kg combined for a plain B; above that you need B96 up to 4,250 kg, or B+E beyond.

Does the B96 require a theory exam?

No. The B96 has no extra theory test. You take two practical tests, one manoeuvring off the road and one driving on the road, both with the trailer attached. It upgrades your existing Permiso B.

Is it the trailer's actual weight or its MMA that counts?

Its MMA, the maximum authorised mass printed on the papers, not what you load on the day. A trailer rated over 750 kg counts as a heavy trailer even when it is nearly empty, so always check the rating.

Do I need to insure a small trailer?

Trailers up to 750 kg are treated as an extension of the towing car in most respects, but your car policy should cover towing. Trailers over 750 kg need their own registration, their own insurance and a passed ITV.

What happens if my combined weight is just over 3,500 kg?

Even a small amount over the 3,500 kg combined limit means a plain Permiso B is not enough. You need the B96 up to 4,250 kg combined, or the B+E above that. Always add the two MMA figures before you set off.

Sources

• Reglamento General de Circulacion (Real Decreto 1428/2003).

Last updated: August 2026.