The Nationwide building society has told HM Revenue and Customs (HMRC) it may have difficulty providing them with expatriates’ account details, a report suggests.
The building society has been in "active discussion" with HMRC, the Times reported the lender as saying.
"However, we do not believe our records enable us to identify those customers who live in the UK and have an offshore account," Nationwide has claimed.
HMRC has recently gained permission to ask lenders to produce the accounts of expatriates who have money saved abroad.
The move by the government is designed to identify people who still owe tax, although HMRC had announced a period of grace, during which expatriates would only face a ten per cent bill on outstanding balances.
Moving abroad requires expatriates to pay close attention to their finances and also consider if they should take out international health insurance before they leave.