I came accross the site below for locating those lost or dormant bacnk accounts, and further down the NS&I service for searching for your premium bonds.http://www.mylostaccount.org.uk/
mylostaccount.org.uk - the FREE service that helps you trace your lost accounts and savings
If you think you may have lost touch with your account or savings, this website will guide you through some simple steps to help reunite you with your money.
This is a FREE service and is brought to you by the British Bankers Association, the Building Societies Association and National Savings and Investments. Together we represent most of the firms that offer savings and current accounts in the UK. So if you need to trace a lost account, this is the place to start.
To get started, just click the yellow start search button and follow the simple steps.
You can visit the help section at any time for more detailed information.
Primum Bonds service :-http://www.nsandi.com/help/tracing_service.jsp
Finding lost savings and investments
Here we explain how customers can ask us to trace any savings or investments they think they may have with us. The service can also be used to track down funds of deceased relatives or clients, provided you are legally empowered to act for that person - for example, under Power of Attorney. Follow the links below for a summary of our Tracing Service, or for full details you can download a brochure. To use the service, just download and complete the form then return it to us.