Parents earning over £50,000 a year in households where child benefit has been claimed between January and April must register with HMRC by 5th October or face a fine.
This does not apply to people already enrolled in the self-assessment system, but those who haven’t previously completed a tax return must register so that HMRC knows how much extra tax to levy to ‘claw back’ some or all of their child benefit under new rules that apply from January 2013.