I am no expert Trousers but any contributions you made would have been subject to tax relief at the basic level. You are entitled to claim back the additional 15% hence your claim - but I could stand corrected on this by an accountant. Actually, I use Taxcalc software to submit my returns online and for the £25 you pay each year it doesn't half make the job much easier. It includes help on issues like yours (and cheaper than an accountant). Furthermore you can copy the previous year's claim into this year and just adjust the numbers. (I don't work for them by the way )