The Society is a registered charity, and so if you are a UK taxpayer the Gift Aid scheme allows us to reclaim the tax that you have already paid on your subscription. This means that the value of your subscription is considerably increased, but at no cost to you. All you have to do is to complete the declaration at the end of the application form.
The amount of tax that you pay in any one tax year needs to be at least equal to the total amount that will be reclaimed on all your Gift Aid donations. You should not make a declaration if you are claiming your subscription as an expense against tax.