Just read this on the gov website -
If you’re a higher-rate taxpayer
You can claim back the difference between the tax you’ve paid on the donation and what the charity got back when you fill in your Self Assessment tax return. It’s the same if you live in Scotland. Do this either:
through your Self Assessment tax return
by contacting HM Revenue and Customs (HMRC) and asking them to amend your tax code
Example
You donate £100 to charity - they claim Gift Aid to make your donation £125. You pay 40% tax so you can personally claim back £25.00 (£125 x 20%).
With Payroll Giving, you do not pay the difference between the higher and basic rate of tax on your donation.
https://www.gov.uk/donating-to-charity/gift-aid