More than 220,000 middle class parents face fines from HMRC in child benefit crackdown Tax experts criticised Mr Osborne last night for a "dysfunctional" crackdown on the benefits system saying the rush to meet the HMRC deadline threatened to trigger chaos. Chas Roy-Chowdury, head of taxation at the Association of Chartered Certified Accountants, said: "I really do worry that whatever HMRC is saying there are going to be lots of people who find out too late they are expected to be paying something back, that they've missed a deadline and could well be facing a penalty. There are large numbers of people who have no idea this affects them and they don't realise self- assessment is something they are now going to be drawn into. It's such a dysfunctional way of taxing people. In most cases the person in a household who doesn't receive the benefit is going to have to pay for something his or her partner is getting. Think about where couples are separating for example. Claire Paye, spokeswoman for Mothers at Home Matter, said the tax crackdown suggested the Coalition did not value mums who decide to stay at home and look after their children, or carry out community work. She said: "It seems unfair that two parents both earning £40,000 a year can continue to receive child benefit where a household where one earns £50,000 will not. It's completely disjointed and to me shows the Government simply does not put a value on mothers staying at home and being there for their children. The new thresholds took effect from January 7 but HMRC claims an estimated 220,000 of 1.1 million affected parents still have yet to register to fill out the self-assessment forms. HMRC last night insisted only those seen to be "evading" paying back child benefit faced a fine of 100 per cent of the amount they owe. A spokesman added that even those missing the October 5th deadline could escape a penalty provided they pay all the tax they owe by January 31. He said: "We are reminding anyone that needs to register that they should do so as soon as possible to ensure they pay the right amount of tax charge due." But Netmums founder Siobhan Freegard said: " With HMRC potentially facing hundreds of thousands of extra self assessment forms and the extra work and expense to claim back the charge it will be interesting to see how much it really saves. Many parents will feel a simpler system is needed.