The band changes don't come in until next year, but as of next month, there are working tax credits that benefit anyone earning up to £16,400 - by more than they will be losing out come the changes next year. My very rough BOE calculation came out at £15675 as break-even, which made the tax credit thing make even more sense, but this doesn't include NI. (Not sure where £18,600 comes from - I make it a change in 10% on the £2090, which equates to £10450 for the reduction of 2% to kick in - add £10450 to the allowance of £5225, and you get £15675. I've probably missed something obvious, though.)