Thousands of British expats living in EU countries have received letters from banks telling them their UK current accounts and credit cards will be closed after Brexit.
The Financial Conduct Authority (FCA) has stressed to banks that they must give at least two months' notice of plans to close any accounts in credit.
It said some were not informing customers in good time, but only certain banks plan to shut accounts.
While not all the roughly 1.3million UK citizens living in the EU will be hit, customers of Barclays, Lloyds and the private bank Coutts living in some of the most popular destinations for expats, including France, Portugal and Spain will have accounts closed if they can no longer prove a UK address.
HSBC, NatWest and Santander have said they will monitor the state of the negotiations, but have no plans to close any customers' accounts at this stage.
Rob Hallums, founder of the financial website Experts for Expats, said last week: "There are options available and you should not make snap decisions without doing the necessary research first, so be sure to do your own research into the best options available."
Hallums added: "One of the biggest issues that British expats face and that affects so much of their international lives is the currency factor – especially in the current turbulent economic times."
"With global currencies fluctuating massively, we believe it is essential for expats to not just accept the exchange rate at any given time, but that they are able to transfer or exchange money when they can get maximum return in their local currency, and without paying bank charges on top."
Following the UK's full departure from the EU, UK banks will no longer be allowed to provide services to customers in the EU without the right banking licences.