As of 2014, the currency used in Wales is the British pound sterling, or GBP. Since Wales is a country within the United Kingdom, it uses the same currency as the rest of the countries in the United Kingdom, which are England, Scotland and Northern Ireland.
The Bank of England acts as the central bank for Wales, which means that it's responsible for issuing currency. The Royal Mint, which is responsible for issuing coins throughout the entire United Kingdom, is located in southern Wales, in the city of Llantrisant. The entire economy of Wales is closely connected with the rest of the United Kingdom, and to a lesser extent, the rest of Europe.