During January, February or March you may get a PAYE Coding Notice from HMRC telling you what your new tax code will be for the tax year 2012-13. Your new tax code will be used by your employer or pension provider from the 6 April 2012 to make sure you pay the right amount of tax.
Not everyone needs to get a Coding Notice, so don't worry if you don't receive one - your employer or pension provider will still be able to update your tax code on the 6 April.
Your Coding Notice is for you to keep.
HMRC will send your new code to your employer or pension provider.