Small donations can be claimed under Gift Aid for donations under £20, donated via cash or contactless credit card.
Unlike regular donations, you do not need to provide full donor information or Gift Aid declarations to claim on small donations.
After enabling Gift Aid, payments have a "Small donation?" checkbox. Checking this will flag the donation as a small donation.
Small donations have a different set of eligibility criteria:
See this page on eligibility for more information.
Note: you can claim up to a maximum of £2,000 in small donations in a single tax year. Beacon does not check this for you - you need to make sure you don't accidentally claim too much.