Can I use EU region xbox live gold in the UK?

Regions are countries so yes it should because EU is a continent & UK is a country.

If it is uk region sure knock yourself out

Xbox live regions are countries NOT continents

I used to work in Import/Export so have a good knowledge of the abbreviations of different countries & regions.

EU has always been short for Europe.The problem is that because European Union has also been shortened to EU over the past few years things have got a bit confusing at times

They should just put U.K. on digital codes to make things simpler & avoid confusion & maybe they will in the future.

EU has always stood for Europe,not for European Union,so it's not a mistake on Microsofts part.

Some codes sometimes say U.K. & Europe but that's been a thing long before we left the European Union.

Not sure Daft Badger. When we Google'd the correct meaning of EU to find a reputable source we get:

The European Union (EU) is an economic and political union of 27 countries. It operates an internal (or single) market which allows free movement of goods, capital, services and people between member states. The EU countries are: Austria, Belgium, Bulgaria, Croatia, Republic of Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Poland, Portugal, Romania, Slovakia, Slovenia, Spain and Sweden
https://www.gov.uk/eu-eea#:~:text=The%20European%20Union%20(%20EU%20)%20is,and%20people%20between%20member%20states.

... but as mentioned Microsoft may have meant European Union and these are very old codes.