If your credit card doesn't have a GBP account, but only RMB and USD accounts, and it is settled through the VISA/ MasterCard network, then the GBP transaction will be converted into US dollars, such as USD account, and then USD will be converted into RMB when repaying, so some banks will also have currency exchange fees at these two exchange rates, which is really not cost-effective.

Our bank is a CCB credit card, and the single-logo VISA card or single-logo master card has the function of full currency, that is, the foreign currency of the transaction is automatically converted into RMB, and there is no currency exchange fee, which is better.