The maximum amount of underpayment which can be coded out in 2012/2013 and future years has now been increased to £2,999.99 (previously £1,999.99)

This means, if you have underpaid tax for the previous tax year, you can apply to have your PAYE Code reduced by an amount of up to £2999.99 in the following year to cover the underpayment of tax. This means that you are spreading the cost of the payment over the next full year.