Tax rebate for this year

[theboyfold]

Is there anybody who would be able to me work out how much tax I should have paid so far this year, and how tax rebates work?

I've been on BR since the start of the financial year and have just been given a code of 487L which I've been told is a code that will allow me to reclaim the tax that I shouldn't have paid.

I've checked out the difference between BR and my new code using http://yahoo.digita.com/taxcentral/home/employment/p and it's about £110. Does it work that I'm then owed the difference times the number of months I've been over paying. The number I have been given is half of what the tax office estimated.

If you need more details and figures and are happy to help me out, please email me.

Thanks in advance.