How this is calculated
When you tick the Gift Aid box, your donation is treated as if it had already been reduced by basic rate tax, currently 20.0%. The charity grosses your payment back up and reclaims the difference from HMRC, so a £1,000 donation becomes worth £1,250 to the charity, with HMRC providing the extra £250.
If you pay tax at the higher or additional rate, you are entitled to claim back the difference between your rate and the basic rate on the grossed-up amount, since you would otherwise have paid tax on that income at your higher rate before donating it.
The calculator grosses up your donation to find the charity's total, works out the basic rate top-up HMRC pays the charity, then calculates your personal relief as the extra percentage points between your marginal rate and the basic rate, applied to the grossed-up figure.
Claiming your relief
Higher and additional rate relief on Gift Aid donations is not given automatically. You need to declare your donations on your self-assessment tax return, or ask HMRC to adjust your tax code if you do not otherwise file a return.
You can also elect to carry a donation back to the previous tax year if you make the claim before you file that year's return, which can be useful if your income or tax rate was higher in the earlier year.
Points for directors and company owners
A company can also make charitable donations directly and deduct them from taxable profit for corporation tax purposes, which is often more efficient than a director donating personally out of dividends that have already been taxed.
Where a director prefers to donate personally, making the Gift Aid declaration correctly and keeping records of all donations across the year makes claiming higher-rate relief straightforward at self-assessment time, rather than trying to reconstruct the figures later.
What this means for your company
Treat the result as a planning figure for the 2026/27 tax year. If it changes what you were about to do, take a director's salary, a dividend, a large asset purchase or a filing decision, check it against your own accounts first. We can review the position with you and confirm the tax treatment before you commit.
Frequently asked questions
How does Gift Aid benefit the charity?
Gift Aid allows the charity to reclaim basic rate tax on your donation from HMRC, currently adding 25p for every £1 you give, so a £1,000 donation is worth £1,250 to the charity at no extra cost to you.
Do I get anything back personally?
If you pay tax at the higher or additional rate, you can claim back the difference between your rate and the basic rate on the grossed-up donation through your self-assessment return, reducing your own tax bill.
What if I do not pay enough tax to cover the Gift Aid claimed?
You must have paid enough UK income tax or capital gains tax in the year to cover the tax reclaimed by all the charities you support under Gift Aid, or HMRC can ask you to pay the shortfall.
Can a limited company use Gift Aid?
No, Gift Aid is a personal tax relief. A company makes qualifying charitable donations directly and deducts the payment from its profits for corporation tax purposes instead, which achieves a broadly similar result at company level.