If you aren’t planning on residing in the United Kingdom for an extensive length of time, and the vehicle is already in the EU then you can use your foreign plates without registering or taxing your vehicle in the UK.
This is only allowed if you are only visiting the United Kingdom and do not plan to live here. For any permanent residency – a registration of your vehicle will be required.
The vehicle must be registered, taxed, and insured in the country of origin. Failure to do so could create issues should there be an accident.
Your vehicle can only reside in the United Kingdom for a total of 6 months. Although if it is for numerous short visits over a 12 month period that is also acceptable.
If you decide to keep your vehicle in the United Kingdom for a period longer than that, please don’t hesitate to get in touch regarding registration.