For those of you out there that don't know this, you can e-mail your local paye/tax office and ask them to check your taxes back as far as 2002(P21 balancing statement) then they will send you out a balancing statement and if they owe you money a check will come before the statement.
Use this link to fine the e-mail address of your loacal tax office, scroll to the bottom of the page where it says "Open Contact Locator:
Click here to use our Contact Locator." and just type in your pps number.
And e-mail them giving your pps number saying you want your taxes checked from 2002 till the present day, they will not go past 2002 as they are "statue barred" whatever the hell that means, but if you want you can invoke the "data protection act" to get records previous to 2002 if they have them.I am currently trying to get these records for myself so i will let you know what happens.
I did this and I got 4,000 euro back (new car for me..woohoo) 1,400 of that was for 2005 alone, the robbing so and so's.
So do it, you could be owed some cash.