The Income Tax (Indexation) Order 2010
For the tax year 2011–12 this Order replaces certain amounts specified in the Income Tax Act 2007 with new, increased amounts. In accordance with the method provided by sections 21 and 57, the increases are calculated by reference to the increase in the retail prices index. Where the retail prices index for the September before the start of the tax year is higher than it was for the previous September an order must be made replacing the amounts.