Tax blunder: possible loophole emerges

Experts said people hit with an unexpected tax demand may be able to refuse to pay up as HMRC could have exceeded its own time limits in which to ask for the money. Under tax rules HMRC must issue demands for underpaid tax within 12 months of the end of the tax year in which it became aware that people had underpaid.

But if people provided HMRC with all the information they needed to get their tax code right, it should have used this information within 12 months of the end of the tax year in which it was received to claw back the extra money.