I found the answer to my own question.

http://www.direct.gov.uk/en/MoneyTaxAndBenefits/Taxes/TaxOnSavingsAndInvestments/DG_4015739

> Tax is charged on your interest at a rate of 20% as standard

> If you are a 22% tax payer, you don't need to do anything.

> If you are a 0% tax payer, it is your own responsibility to fill out the forms at your bank to stop the 20% tax payment

> If you are a 10% tax payer, you pay 20% tax and then claim the other 10% back at the end of the finacial year from Revenues and Customs

> If you are a higher rate tax payer, you must inform the Tax Office and arrange for the payment of the HRT