BDO has cast doubt on government claims that the married couples tax giveaway announced in last week's Autumn Statement will result in a £800m windfall for taxpayers, saying the relief will be too complicated for many people to claim and for HMRC to administer.

The tax break applies if couples who are married or in a civil partnership are both basic rate taxpayers with one spouse earning less than the personal allowance. From April 2015, married couples and civil partners will be able to transfer £1,000 of their income tax personal allowance to their spouse, so that together they will pay less tax. The transferable amount is set to increase in future years in proportion to the personal allowance.

HMRC says it anticipates that 4.1m couples will be eligible for a tax giveaway of up to £196 benefit per annum per couple with 84% of the winners expected to be male spouses.

However Richard Rose, BDO tax partner, said: ;As with many targeted tax incentives for individuals, if the hoops that taxpayers have to jump through to get the benefit are too complicated then there is unlikely to be a great take up.'

Rose argues that many who would be eligible may not realise that they are entitled to make a claim or will be put off by the complexity, especially when they are not used to dealing with tax matters.

'In addition, it is unlikely that HMRC, given current resource constraints and its move towards digital interaction with taxpayers, will be able to cope with subsequent changes when, for example, relief has been given but then needs to be clawed back due to a change in circumstances,' Rose said.