There is a free tracing service called 'mylostaccount' to find lost bank accounts. The service brings together the three tracing schemes of the British Bankers' Association (BBA), the Building Societies Association (BSA) and National Savings and Investments (NS&I) into a single website (www.mylostaccount.org.uk) and is free of charge.
The service offers a way for savers to search for their lost accounts by enabling them to complete one form to search the majority of banks and building societies and National Savings & Investments (NS&I). An account may be defined as 'lost' if you have not made any withdrawals or deposits for a set period (typically three years in the case of a savings account and one year for a current account) and the bank has not heard that you wish to keep the account open. The monies remain the account holders property but may need to be searched for as a lost account.
The government's dormant assets scheme allows money in accounts that have been dormant for at least fifteen years to be made available for certain qualifying charitable and community causes. The original account holder retains the rights to repayment of any monies within the scheme after providing satisfactory proof that the money is theirs.