UCU members are eligible for tax relief on their subscription fees, which come under Professional Subscriptions and Fees with HMRC.
Please use this guide for info on how to claim: Claiming Tax Relief on UCU Subs Guide (1st page is UCU’s advice, centred on using the paper form, and 2nd page onwards is a guide to using the online Government portal);
It is a rather complicated process, as tax years and academic years are different, so the template helps you to calculate the total per tax year needed to put in the claim, and the guide takes you through how to submit your claim on the online portal. If you have Direct Debit records going back far enough, this would be a much easier way to calculate your total.