Make a one off donation

I want all donations I've made to you in the past four years and all donations in future to be treated as Gift Aid donations until I notify you otherwise.
I am a UK taxpayer and understand that if I pay less Income Tax and/or Capital Gains Tax than the amount of Gift Aid claimed on all my donations in that tax year it is my responsibility to pay any difference.
We will claim 25p on every £1 you donate.