When fitting a towbar or towing a trailer, caravan or bike rack, the electrical connection is just as important as the towbar itself. Every trailer or accessory needs power for its road lights to ensure safety in traffic. That power comes through a plug and socket system that connects your vehicle to what you are towing.
The three most common systems in the UK are 7 pin, 8 pin and 13 pin. Each has different wiring layouts, features and uses. Choosing the right one depends on what you tow, from simple utility trailers and cycle carriers through to modern caravans with on-board power. This guide explains the differences, shows the wiring diagrams, and includes step by step video tutorials for 7 pin and 8 pin plugs so you can choose the right option for your setup.
Jump to section
- 7 pin trailer plugs
- 8 pin trailer plugs
- 13 pin trailer plugs
- 7 pin vs 8 pin vs 13 pin
- Frequently asked questions
- Need help choosing or fitting
7 pin trailer plugs (12N)
The 7 pin plug, also called 12N, is the long-established UK standard for basic towing electrics. It powers the essential road lights: tail lamps, brake lights, indicators and fog lamp. It does not include a reverse light or 12V power feeds, which is why it is still common on simple trailers and light boards but less suitable for modern caravans and more complex towing setups. [oai_citation:1‡GT Towing](https://gttowing.co.uk/blog/uk-trailer-plug-and-socket-guide-7-pin-8-pin-and-13-pin-explained/)
What 7 pin plugs are used for
- Small trailers for domestic and light commercial use
- Trailer light boards and some cycle carriers
- Older commercial, large domestic and horse trailers
- Some older caravans when paired with a second 7 pin 12S power socket
Buy 7 pin plugs Buy 7 pin sockets
8 pin trailer plugs
The 8 pin system is the newer UK standard for trailer lighting on many modern trailers. The extra pin is typically used for a reverse light, giving it an advantage over 7 pin while keeping the setup fairly simple. This makes 8 pin a common choice for many post-2013 trailers and newer accessory carriers, but it is still worth checking the exact wiring layout before replacing a plug or socket. [oai_citation:2‡GT Towing](https://gttowing.co.uk/blog/uk-trailer-plug-and-socket-guide-7-pin-8-pin-and-13-pin-explained/)
What 8 pin plugs are used for
- Most new trailers built after 2013
- Many modern cycle carriers and rear mounted accessories
- All Ifor Williams Trailers, Brian James and Indespension trailers built after 2013
- Thule products rolled over to 8 pin from 2021
Buy 8 pin plugs Buy 8 pin sockets
13 pin trailer plugs
The 13 pin system is the modern UK and European standard for more advanced towing electrics. It combines all road lights, reverse, plus permanent and switched 12V power in one connector. The twist-lock design is more secure and better sealed against water and dirt, which is why it has replaced the older twin 7 pin setup on most modern caravans and many larger trailers. [oai_citation:3‡GT Towing](https://gttowing.co.uk/blog/uk-trailer-plug-and-socket-guide-7-pin-8-pin-and-13-pin-explained/)
What 13 pin plugs are used for
- Modern caravans with reverse lights, leisure battery charging and fridge power
- Larger trailers with reverse lighting and auxiliary circuits
- European imports, where 13 pin is the standard connector
- Towing setups where a more secure, weather-resistant plug is preferred
Buy 13 pin plugs Buy 13 pin sockets
Quick comparison: 7 pin vs 8 pin vs 13 pin
| Feature | 7 pin | 8 pin | 13 pin |
|---|---|---|---|
| Road lights | Yes | Yes | Yes |
| Reverse light | No | Yes | Yes |
| 12V power feeds | No | No | Permanent and switched |
| Water resistant design | Basic | Sealed twist-lock | Sealed twist-lock |
| Locking mechanism | Push fit | Twist lock | Twist lock |
| Typical use | Small trailers, light boards | Modern trailers, bike racks | Caravans, larger trailers, auxiliary power |
In simple terms, 7 pin is best for basic road lighting, 8 pin adds reverse for newer trailers, and 13 pin is the best option if you need a fully featured, modern towing connection. That matches the way the current GT Towing guide already positions each system. [oai_citation:4‡GT Towing](https://gttowing.co.uk/blog/uk-trailer-plug-and-socket-guide-7-pin-8-pin-and-13-pin-explained/)
Frequently asked questions
Is a 7 pin socket still legal in the UK?
Yes. A 7 pin socket is still legal for basic trailers and light boards because it covers the core road-lighting functions required for towing. [oai_citation:5‡GT Towing](https://gttowing.co.uk/blog/uk-trailer-plug-and-socket-guide-7-pin-8-pin-and-13-pin-explained/)
What is the difference between 12N and 12S?
12N is the older 7 pin socket used for lighting functions. 12S was a second 7 pin socket used mainly on caravans for supplementary power such as fridge and charging circuits. Modern caravans now use a single 13 pin socket instead. [oai_citation:6‡GT Towing](https://gttowing.co.uk/blog/uk-trailer-plug-and-socket-guide-7-pin-8-pin-and-13-pin-explained/)
Can I tow a caravan with just 7 pin?
Yes, for legal road lights, but a 7 pin setup will not support the additional functions many caravans need, such as fridge power, battery charging and some stability systems. For regular caravan towing, 13 pin is the better long-term solution. [oai_citation:7‡GT Towing](https://gttowing.co.uk/blog/uk-trailer-plug-and-socket-guide-7-pin-8-pin-and-13-pin-explained/)
Can I use an adapter between 7 pin and 13 pin?
Yes. Adapters are available and can be useful if you only occasionally tow something with a different plug type. For frequent towing, a correctly matched socket is usually the more reliable option. [oai_citation:8‡GT Towing](https://gttowing.co.uk/blog/uk-trailer-plug-and-socket-guide-7-pin-8-pin-and-13-pin-explained/)
Why do caravans use 13 pin?
Because caravans need more than lighting alone. A 13 pin system can provide reverse light, fridge power, leisure battery charging and other auxiliary functions in one more secure connector. [oai_citation:9‡GT Towing](https://gttowing.co.uk/blog/uk-trailer-plug-and-socket-guide-7-pin-8-pin-and-13-pin-explained/)
Need help choosing or fitting?
At GT Towing we supply and fit all types of towbar electrics, from basic 7 pin plugs through to full 13 pin dedicated kits. If you are not sure which setup you need, our team can help match your electrics to your vehicle and whatever you are towing. The site also has a separate wiring diagram resource page if you want the diagram-focused version of this information. [oai_citation:10‡GT Towing](https://gttowing.co.uk/blog/uk-trailer-plug-and-socket-guide-7-pin-8-pin-and-13-pin-explained/)
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