Regulations and Legal Requirements for the Use of Trailers in Spain (2025)

March 5, 2025

The use of trailers in Spain is regulated by national laws (General Vehicle Regulations, General Traffic Regulations, General Driver Regulations, among others) in accordance with European directives. Below, we detail the most important legal requirements regarding driving licenses, trailer weight categories, weight limits, mandatory signage and lighting, territorial differences, technical inspections (ITV), and the relationship with European Union regulations, including considerations for transporting trailers to other EU countries.

Driving licenses according to the weight and type of trailer

The type of driving licence required to tow a trailer depends on the Maximum Authorised Mass (MAM) of the trailer and the vehicle-trailer combination:

B Permit (passenger cars up to 3,500 kg): With a standard B license (vehicles up to 3,500 kg GVW) you can tow trailers light up to 750 kg GVW without the need for any additional permit. It is also possible to tow a trailer weighing more than 750 kg with a B permit. provided that the sum of the GVW of the towing vehicle and the trailer does not exceed 3,500 kgIn these cases, no additional special authorization is required.

Authorization B96: If you want to tow a trailer of more than 750 kg of MMA with a passenger car weighing up to 3,500 kg, and the resulting set exceeds 3,500 kg but does not exceed 4,250 kg, the B96 permit is mandatory. This is an extension of the B permit, obtained by passing a specific practical maneuvering test (it does not require an additional theory exam). With the B96, you can, for example, drive a car with a GVW of 3,500 kg towing a trailer of up to ~750 kg additional, or a lighter car with a heavier trailer, provided the total weight is ≤ 4,250 kg.

B+E Permit: If the set exceeds 4,250 kg Or if the trailer weighs more than 750 kg and the above cannot be met, then a B+E permit is required. The B+E permit allows you to drive combinations of vehicles weighing up to approximately 7,000 kg, typically a passenger car (≤3,500 kg) with a trailer with a GVW of up to 3,500 kg. For example, a B+E permit would be required for a car towing a large caravan with a GVW of around 3,000 kg.

Class C+E / D+E permits (heavy vehicles): If the towing vehicle is of a higher category (trucks, industrial vehicles or buses), the same rules apply, but the corresponding truck or bus permit plus the E authorization will be required. For example, a truck >3,500 kg with a trailer will require C+E permit, and a bus with a trailer, D+E permit, following the categories defined by European driving license regulations. These combinations can lead to much higher GVWs (in heavy goods transport, the total weight can reach up to 40 tons in the EU, with the appropriate licenses).

NoteThe above categories are established in Spanish regulations in accordance with EU Directive 2006/126/EC on driving licences. Spain has incorporated these definitions into the General Regulations for Drivers (e.g., Royal Decree 818/2009), so the equivalences (B, B+E, etc.) are valid throughout the European Union.

Maximum weight limits and trailer categories

Legally, trailers are classified into categories primarily by their Maximum Authorized Mass (MAM), which is the maximum trailer weight (structure + load) allowed:

Light trailers (O1): They are those with MMA up to 750 kgThese trailers do not require their own registration or insurance; they use the towing vehicle's registration number and are legally considered an extension of the passenger vehicle. Since they weigh less than 750 kg, they can be hitched with a standard B permit (within the limits mentioned above).
Non-light or heavy trailers (O2): They are trailers with MMA greater than 750 kg (typically up to 3,500 kg in the case of passenger car trailers). These Yeah require a own red license plate and a vehicle registration independent, in addition to specific compulsory insurance. In Spain, heavy trailers carry two plates On the rear: its own registration plate (red background with the initial letter "R") and a duplicate plate of the towing vehicle. To tow this type of trailer, you need a B96 or B+E permit, depending on the combined weight (as explained in the previous section).
O3 and O4 category trailers: These are trailers with a GVM exceeding 3,500 kg (common in trucks and heavy transport trailers). These, together with the semi-trailers Articulated vehicles fall within the category of heavy goods vehicles. Their use requires appropriate towing vehicles (category N) and drivers with professional permits (C+E, etc.). Truck-trailer or trailer combinations are subject to weight and dimension limits established by European regulations (Directive 96/53/EC) – for example, maximum masses of 40 tonnes and maximum lengths of 18.75 m for truck-trailer combinations. In any case, these heavy-duty trailers must register and comply with stricter technical regulations (brakes, signaling, etc.), just like the O2.
General weight limits: In addition to legal MMA, it is important to note that the towing capacity indicated by the manufacturer of the towing vehicle cannot be exceededThe maximum towable weight is specified on each vehicle's technical sheet; this figure is a technical limit that must not be exceeded for safety and legal reasons. In other words, although permit regulations allow a certain combination of weights, the lower limit must always be respected: the one indicated by the vehicle manufacturer or the one established on the vehicle's MOT (Inspection Certificate). Towing more weight than authorized for the vehicle is punishable and dangerous.

Trailer signage, lighting, and safety requirements

When towing a trailer, the law requires compliance with a series of signaling and lighting requirements to ensure visibility and correct identification of the trailer, as well as certain active and passive safety measures:

License plates and identification plates: As mentioned, the light trailers They do not have their own license plate, but the same license plate as the car. A duplicate license plate of the towing vehicle must be fitted to the rear of the trailer (usually when the trailer obscures the car's license plate). However, heavy trailers must be registered: they carry their red license plate with trailer number (letter R) and, additionally, another plate with the registration of the towing vehicle visible on the back. In this way, both elements of the set are identified.

Mandatory lighting and illumination: All trailers must be fitted with rear lighting devices similar to those on a vehicle, as they can obscure the car's lights when coupled. The trailer must have rear position lights (red lights), brake lights, rear turn signals, and rear license plate lighting. In addition, you must carry Red rear reflectors in triangular shape (exclusive to trailers). They are also mandatory white front reflectors (not triangular) and amber sides on the trailer, so that the vehicle can be seen from all angles. There are additional requirements depending on the size: for example, if the trailer exceeds 1.60 m in width must also carry white front position lights; if it exceeds 2.10 m wide, needs clearance lights (two white front ones and two red back ones at the top, to indicate the width); and if your length is greater than 6 m, must incorporate side marker lights (markers) along the side. All these devices must be approved and in correct operation. It is mandatory to connect the electrical wiring from the trailer to the vehicle using the corresponding socket, so that all the trailer lights are activated together with those of the car.

Signaling of protruding loads: If the load transported on the trailer protrudes from behind it (for example, bars, pipes, bicycles, etc.), it is mandatory to mark said load with the plate V-20 (50x50 cm red and white reflective panel). Regulations require one or two V-20 plates to be placed at the end of the protruding load, perpendicular to the vehicle's axis, to alert other drivers. In general, for passenger cars and their trailers, the load may not protrude more than 10% of the vehicle's length (15% if the load is indivisible) from the rear; any load exceeding the vehicle's floor must be marked with a V-20 (by placing a plaqueif the load does not occupy the entire width, or two plates (if it occupies the entire rear width) according to Article 15 of the General Traffic Regulations. Likewise, no load may protrude in front of the towing vehicle. These limits and signs are important for complying with the law and avoiding penalties.

Safety measures on the hitch: It is mandatory to use a approved coupling system for towing. The fixed ball or hitch must be approved and installed in an authorized workshop, and its installation must be legalized on the vehicle's technical sheet through a vehicle inspection. Furthermore, All light trailers without brakes must have a safety chain or cable. that connects the trailer to the towing vehicle. This safety chain serves as a secondary restraint measure: in the event of accidental detachment of the hitch, it prevents the trailer from completely releasing, holding it to the vehicle so it can be stopped with greater control. Heavy trailers with an inertia brake system usually have a safety chain. emergency brake cable which, if the trailer is uncoupled, automatically activates the trailer brakes. It is essential to always check that the docking system is properly secured before starting the journey (pin or hitch lock closed, chain/cable correctly connected).

Brakes: The trailers with a GVW > 750 kg (heavy trailers) must be provided with braking system(usually an inertia brake or automatic braking system) in accordance with European approvals, given that they tow a considerable weight. On the other hand, light trailers (≤750 kg) are not required to have their own brakes. Many light trailers do not have a service brake, relying solely on the brakes of the towing vehicle. However, all trailers over 750 kg also have a brake. parking brake (handbrake) to immobilize them when they are disconnected or parked. It is important to check the correct operation of the inertia and parking brakes at the ITV and before travelling, if applicable.

Mirrors and visibility: If the trailer is wider than the towing vehicle or limits rear visibility with the standard mirrors, the driver must equip additional rearview mirrors Longer-range mirrors. These extendable mirrors allow you to monitor the sides of the trailer and are mandatory when the trailer obstructs sufficient rearview vision. For example, when towing a wide caravan, it is often necessary to install additional mirrors on the car.

Speed: When driving with a trailer, there are specific speed limits lower than those of passenger cars without a trailer. In Spain, driving with a trailer limits the maximum speed to 90 km/h on motorways and dual carriageways, and 80 km/h on conventional roads, even if the car itself could go faster. On urban roads, the same general speed limits of 50 km/h (or 30 km/h on single-lane roads in each direction) apply, since there is no specific urban speed reduction beyond what is indicated by local signs. These speed restrictions, established in the General Traffic Regulations, aim to ensure safety, since with a trailer, stability is reduced and braking distance increases. It is essential to respect these limits; exceeding the speed limit with a trailer carries administrative penalties and significantly increases the risk of accidents (due to trailer swaying or "snake-like" behavior, loss of control, etc.).

Regulatory differences between autonomous communities

In Spain, traffic and vehicle regulations (including those relating to trailers) are of state scope, hence There are no substantial differences in regulations between autonomous communitiesThe General Vehicle Regulations, the Traffic Regulations and the Drivers Regulations are applicable throughout the national territory, with the General Directorate of Traffic (DGT) and other authorities (Army, regional police, etc., in their respective areas) are responsible for its compliance.

It is worth mentioning that, although the Traffic competition is transferred to Catalonia and the Basque Country (and partially to Navarre), these communities apply the same state legal framework, only the administration in charge of managing it changes. Therefore, Requirements regarding weight, registration, permits or trailer equipment do not vary from one community to another..

They may exist administrative or management differences: For example, the fees for MOT inspections may vary depending on the region, or the control campaigns may be more intensive in some areas than in others, but the technical regulations and obligations of the trailer user are equivalent throughout Spain. There may also be municipal ordinances relating to the trailer parking (Some cities regulate the parking of unhitched RVs or trailers on public roads.) But when it comes to road traffic and vehicle requirements, the regulations are common. It's always a good idea to check local regulations if you plan to spend the night with RVs or leave a trailer parked for long periods of time, but all traffic rules apply to the same state regulations.

Technical inspections (ITV) and other administrative requirements

The Technical Vehicle Inspection (ITV) It is a mandatory procedure for most vehicles in Spain, including trailers in certain cases, with the following particularities:

Installing the hitch: Fitting the ball or tow hitch to a vehicle is considered a important reform. After installing the hitch in an authorized workshop, you have a period (generally 15 days) to go to an ITV station and legalize the reform. The vehicle inspection checks that the hitch meets the approval requirements and is properly installed. If approved, the hitch installation is noted on the vehicle's vehicle inspection card (technical data sheet). Driving while towing a trailer without having the hitch legally registered in the vehicle's documents can result in a fine (up to €200 according to the DGT).
Trailer MOT card: Every trailer, even the light ones, has a technical sheet (ITV card) issued at the time of manufacture or first registration, which includes its characteristics (GVM, number of axles, dimensions, coupling system, etc.). In the case of light trailers (≤750 kg), although do not have to register separately, Yes, they must have their technical inspection card. and, where applicable, the hitch approval certificate. This documentation must be kept available. Light trailers They are not subject to passing their own periodic ITV; in fact, for the purposes of the DGT, they are considered part of the towing vehicle and “they are not independent vehicles” in terms of periodic inspection. However, it is necessary to present them at the ITV when the towing vehicle goes to the inspection, so that they can also be visually inspected alongside the vehicle. In practice, this means that if we have a trailer attached when we go to the vehicle inspection, they will check the lights, general condition, etc., of the light trailer at the same time. If we don't have one, it's a good idea to have the documentation in case it's required. In summary: trailers weighing ≤750 kg are exempt from the formal periodic vehicle inspection, but they must be in good condition and have valid documentation; their inspection is carried out indirectly through the vehicle's inspection.
Heavy trailers (>750 kg) and semi-trailers: These are the ones independent vehicles for MOT purposes, and they must pass their own periodic inspections apart from the towing vehicle. Current regulations (after RD 920/2017) establish that the O2 caravans and trailers (>750 kg up to 3,500 kg)They must pass their first ITV at 6 years from the first registration, and then each 2 years up to 10 years old. (After 10 years, some sources indicate that the frequency may become annual; however, for leisure trailers such as caravans it usually remains biennial even after 10 years, unless the regulations change). For other heavy load trailers, a first inspection could previously be applied at 2 years, but with the harmonization of criteria by categories, it is common to first at 6 years old Also on O2. In any case, after a certain age all heavy trailers end up being inspected. at least every year or even every 6 months for very old trailers or trailers of higher categories. It's important to check the exact schedule for the trailer's category and use (e.g., O3/O4 truck trailers have more demanding schedules). Failure to pass the MOT (Spanish Vehicle Inspection) on time with a trailer carries penalties (driving with an expired MOT carries a €200 fine) and, in the event of an accident, could affect your insurance.
Vehicle registration and insurance: Trailers >750 kg have a Own Circulation Permit, issued by the Traffic Department when registering them, just like a car. They must have their own liability insurance policy (mandatory) independent insurance. This is because they are legally considered autonomous vehicles: in the event of an accident, heavy trailers have separate coverage from the car. In contrast, light trailers do not have their own registration permit and do not require separate insurance. Civil liability for damage caused when towed by the car is usually covered by the towing vehicle's insurance policy (although it is advisable). inform the insurer that a light trailer is available, so that it can be included in the policy). The installation of the hitch must also be reported to the insurance company. ImportantAlthough a light trailer is covered by car insurance under liability, if it causes damage while unhitched (e.g., if it comes loose during a maneuver), liability may apply. It's a good idea to insure any trailer if it's going to be used regularly, with at least an addendum on your car policy.
Fees and taxes: Light trailers, when not registered, do not pay registration fees or road tax separately. Heavy trailers, when registered, are subject to the Traffic registration fee (license issuance fee), but are exempt from the Registration Tax (IM) state for emissions, since they are non-motorized vehicles. As for the Vehicle Tax (Mechanical Traction Vehicle Tax – IVTM) Many municipalities also exempt light trailers (because they're not even registered) and apply very low rates to heavy trailers (according to MMA); for example, in some ordinances, trailers under 1,000 kg pay a minimum fee. It's a good idea to check with your local council, but generally the annual tax cost of a heavy trailer is low compared to a passenger car.
Documentation to bring: When towing a heavy trailer, the driver must carry both the towing vehicle documentation (vehicle permit, technical sheet and ITV, insurance) as the of the trailer(trailer registration certificate, trailer MOT card with valid MOT, and trailer insurance). For light trailers, it is advisable to carry the light trailer MOT card and some proof of ownership, even if the vehicle doesn't have a vehicle registration certificate. During a check, the Traffic Department will normally request the light trailer's MOT (Inspection of Vehicle Registration) card to verify its details (MMA, etc.) and the hitch entry in the vehicle's documentation.

Applicable European regulations and adaptation of Spanish law

Spanish trailer regulations are strongly influenced and harmonized by European Union regulations:

Driving licenses: The driving licence categories (B, B+E, C+E, etc.) are defined by the Directive 2006/126/EC (third EU Driving Licence Directive). Spain adopted these definitions in its national regulations, so that a licence issued in Spain qualifies for exactly the same vehicle+trailer combinations in any Member State. For example, the figure of the authorization B96 (which allows sets up to 4,250 kg) comes from said European regulation and is available in several EU countries, although its processing may vary slightly. Likewise, the permit B+E and professional licenses C+E and D+E They are a community standard. In 2024, the EU has considered updates to the Permit Directive to relax certain limits (for example, allowing the B permit to cover up to 4,250 kg for low-emission vehicles), but the standard thresholds for trailers have not been altered. Any modifications at the European level will be transferred to Spanish law once approved and transposed.

Homologation and vehicle categories (type): Trailers, like passenger cars, are subject to European approvalThere is a common EU framework for the type-approval of motor vehicles and their trailers (e.g., Regulation (EU) 2018/858 replaced Directive 2007/46/EC), which defines technical requirements and categories. Within this framework, trailers are classified into categories. O1, O2, O3, O4 according to its GVW, as used in Spain. A trailer manufactured in an EU country with European approval can be registered in any other member country with minimal formalities, thanks to the Certificate of Conformity (CoC)issued by the manufacturer. Spanish legislation (the General Vehicle Regulation, RD 2822/1998 and subsequent amendments) incorporates these EU categories and technical requirements. For example, the requirements for brakes, axles, lighting devices, couplings, etc., for Spanish trailers come from UNECE Regulations or European directives that unify standards. This means that a trailer registered in Spain meets the same safety and construction criteria as in the rest of the EU.

Signage and road safety: Many trailer safety standards originate in Europe. For example, reflective devices (catadioptric), the obligation to brake lights and turn signals, or the demand for brake on trailers >750 kg, are derived from common European regulations (UNECE Regulations 13, 48, etc.). By transposing them, Spain guarantees that a Spanish trailer circulating in Europe is recognized and considered safe, and vice versa. Additionally, the Highway Code It is harmonized in some aspects by international conventions (the Vienna Convention on Road Traffic) to which Spain and other EU countries adhere. This ensures, for example, that the Spanish V-20 sign for outgoing cargo is understandable in other countries (although each country has its own equivalent panels), or that the principles for limiting the dimensions (length, width, height) of loaded vehicles are similar in Europe. However, there may be specific details in each country (for example, in some countries the speed limit for trailers may vary, or they require carrying certain additional equipment such as fire extinguishers in caravans), so it is advisable to check local regulations when traveling abroad with a trailer.

Maximum dimensions and weights in the EU: The European Union sets harmonized maximum limits for dimensions and masses of certain combination vehicles, especially in commercial transport. For non-commercial vehicles (such as passenger cars with a leisure trailer), the rules of each country usually converge, but are not completely unified beyond the approval regulations. In general, the maximum length of a trailer in the EU for tourism is usually ~7-8 meters, and that of a car+trailer set, 18.75 m (although it is rare to achieve this with passenger cars). Spain in its regulations limits the maximum length of a trailer to 12 meters(excluding lance) and the whole set at ~18.75 m, in line with the European directive on weights and dimensions. maximum width of any vehicle (and trailer) is 2.55 m (2.55 m for closed refrigerated trailers) in the EU. The maximum height It is 4 m (Spain adopts 4 m, although other countries allow up to 4.2 m for domestic vehicles, but internationally the limit is usually 4 m). These limits are incorporated into Spanish regulations and do not usually affect passenger trailers (most caravans, for example, are about 2.5 m wide and 2.5-3 m high, with a margin). In short, Spain applies the standard European size limits for trailers, facilitating their free movement within the Union.

Moving trailers within the EU and necessary approvals

When it is intended moving a trailer to another EU country, there are different situations to consider:

Temporary travel with a trailer (tourism or short stays): If a Spanish driver travels with his vehicle and trailer through Europe temporarily (holidays, business trips without changing residence), You do not need to complete additional registration procedures in other countriesUnder EU regulations, the Spanish registration of the car and trailer (if applicable) are valid in any Member State as long as there is no change of residence. In fact, Most of the regulations applicable to cars also apply to trailers. in these situations. That is, you can drive with a light trailer (without your own license plate, using the car's license plate) or with a heavy trailer registered in Spain in EU countries without any problems, as long as you comply with local traffic regulations (for example, respecting the speed limits for trailers in that country, equipping it with the load-signaling plates required by that country, etc.). It is advisable to carry the documentation for both the trailer and the car, and check that the insurance has international coverage (the Green Card or geographic coverage of the liability policy) including the trailer. In general, a trailer legal in Spain is legal in any EU country to circulate temporarily, thanks to the mutual recognition of registrations and approvals.
Permanent transfer and registration in another country: If the owner of the trailer moves his habitual residence to another EU country and takes the trailer with you permanent, you must register the trailer in the new country (same as the towing vehicle) in accordance with the rules of that country. There is no unified "European" registration; each State registers vehicles (including heavy trailers) when they come under its jurisdiction due to residence. The process of registering a trailer within the EU is usually simple if the trailer has European type approval. The following are usually required: presenting the trailer for a technical inspection in the country of destination, providing the original documentation (vehicle permit if you had one, and technical sheet) and the Certificate of Conformity (COC) issued by the manufacturer. With these documents, the authority in the new country will issue a local vehicle registration document and license plate for the trailer. In Spain, for example, registering a trailer from another EU country requires obtaining the Spanish vehicle inspection card (after inspecting the trailer at an vehicle inspection station) and then applying for the license plate at the DGT (General Directorate of Transport and Transportation). COC It greatly simplifies the process, as it certifies that the trailer complies with European approval; if you do not have a COC (for example, an old trailer), you can process a individual approval or a "reduced sheet" by a technical engineer, to demonstrate that it meets the technical requirements. In any case, It is not necessary to re-homologate from scratch If the trailer was already approved in an EU country, the approval is mutually recognized. Only checks are carried out and national documents are issued.
Necessary approvals: To manufacture or import trailers within the EU, you must have a EC approval. Trailers purchased new within the EU already come with their type approval and COC. If anyone intends to matter a trailer from outside the EU, then yes you will face a process of unitary approval, where a technical service will verify that the trailer meets European regulations (lights, brakes, dimensions, etc.) before authorizing its registration. Within the EU, however, virtually all trailers in circulation comply with common regulations. This is why, for example, a used German caravan can be registered in Spain by presenting the appropriate documentation and usually is exempt from adapting components, because it already has EU-approved lights, brakes, and hitches. Adjustments may only be required if there are regulatory differences (for example, special lights), but in practice the requirements are equivalent.

International circulation: When traveling with a trailer through different countries, you must pay attention to any specific requirements: some countries require additional equipment, such as fire extinguisher or extra triangles in caravans; others have traffic restrictions at certain times or on certain roads for vehicles with trailers. However, in the European Union, the trend is toward unification. An important aspect is the approval documentation: It is advisable to bring the Certificate of Conformity or a copy of the vehicle registration form in case of any roadside inspections (especially in heavy transport situations). Also, if the trailer is light and doesn't have its own license plate in Spain, it may be useful to carry a document proving its maximum permissible weight (the MOT card) to show foreign authorities that, according to Spanish law, the trailer doesn't require a license plate. In most cases, European traffic police are familiar with these differences (for example, in France or Germany, an unregistered trailer with a Spanish license plate is considered to weigh less than 750 kg).

In summary, moving a trailer within the EU It does not pose significant obstacles thanks to legal harmonization: temporarily requires nothing more than complying with local traffic regulations, and permanently involves re-registering by presenting a certificate of conformity and passing the local MOT, an administrative procedure similar to that for any vehicle. It is always advisable to check the specific requirements of the destination country (time limits, local taxes, etc.) before a final move to avoid penalties, but the technical and legal equivalence of trailers is guaranteed by current EU regulations.

Sources:

General Directorate of Traffic (DGT) – Permit regulations and tips for driving with a trailer: dgt.es/caravans-and-trailers

General Vehicle Regulations (RD 2822/1998) – technical requirements: citaprevia.cat/luces-obligatorias-itv

General Traffic Regulations (RD 1428/2003) – traffic regulations with trailers: dgt.es

Traffic and Road Safety Magazine (DGT) – informative articles: revista.dgt.es

ITV portals and official documentation – frequency of inspections and registration procedures: lavanguardia.com, administracion.gob.es

All provisions are based on European Union directives and regulations applicable to vehicles and traffic, ensuring consistency between Spanish legislation and the EU regulatory framework.

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