How does Gift Aid work for higher rate taxpayers?
If you pay a higher-rate tax, you can claim the difference between the higher-rate tax (40% or 50%) and the basic-rate tax (20%) on your donation’s total ‘gross’ value.
If you pay Income Tax at a higher or additional rate and want to claim the additional tax relief due. In that case, you must include all Gift Aid donations from your Swiftaid end of year statement on your Self-Assessment tax return or ask HM Revenue and Customs to adjust your tax code.