The rate used by your card provider when paying in local currency will in most cases be lower than that of the merchant, or foreign bank, when paying in sterling. Some retailers outside the UK might automatically assume you want to pay in pounds unless you say otherwise, so always double check the amount before paying.

When traveling in London, you should always choose to pay in British Pounds (GBP) rather than US Dollars (USD) when prompted by a card machine or ATM. This avoids a process called Dynamic Currency Conversion (DCC), where the merchant or the local bank chooses the exchange rate. DCC rates are notoriously poor and often include hidden markups of 3% to 7% on top of the actual exchange rate. By choosing to pay in "Local Currency" (GBP), you ensure that your home bank—which typically offers a much more competitive rate—handles the conversion. In 2026, London is almost entirely a cashless society; from the Underground (using "Contactless" or Apple/Google Pay) to local street markets, physical cash is rarely needed. For the best financial strategy, use a credit or debit card that has no foreign transaction fees, and if a machine asks "Pay in USD or GBP?", always select GBP to keep more of your money in your pocket.