They should have their Premium Bonds holder’s number to hand. This can be found on their Bond record.

Customers are instructed to enter their UK bank account details, and they can then choose to have prizes paid directly into their bank account or reinvested into more Premium Bonds – up to the maximum £50,000.

The savers who opt to use this service will need either an email address or a mobile phone number so that NS&I can notify them of any prize win, either by text message or email.

NS&I says customers who don’t have access to an email address or mobile phone should call 08085 007 007, where call centre staff will be available to provide support.