Tax Returns

I guess I didn't think there would be people that would donate to a charity but then claim tax back for themselves.

Your naivité is endearing. Never change, dearest Hippy, never change.

Because, as the link above shows, if you're a higher rate tax payer than you can claim back some tax too, and that doesn't stop the charity claiming the extra money it can get.

Example 1:

Basic rate tax payer donates £100 to charity and ticks the "Gift Aid" box.
Charity can claim an extra £25 (25p in the £).
Tax payer can't claim anything back personally in this case.

Example 2:

Higher rate tax payer donates £100 to charity and ticks the "Gift Aid" box.
Charity can claim an extra £25 (25p in the £).
Higher rate tax payer can also claim the difference in tax rates (currently 40%-20%=20%) of the total amount (£125 as it includes the original uplift). £125 * 20% = £25.

It's a perk of paying the 40% tax rate.

If you haven't been doing it then you could get a fair chunk of cash back from the Government just for submitting a few Self Assessments. (I have to do one each year anyway so it helps lessen the yearly tax bill.)