Amazingly, from starting to hunt out the necessary paperwork this morning, followed by tracking down my online registration details, trying to print out the working sheets, popping out to get some more ink for the printer, trying again to print, and sitting going through the "transfer box A23 to box A32" and "Insert the lower of boxes A55 and A56 into box A57", I have completed and submitted my tax return today.
And after all that, apparently the tax man owes me 98p!