Martin Lewis urges UK households to 'call HMRC' for a new tax codeThe ITV star, aged 52, says people who earn £80,000 or less who claim Child Benefit don't have to fill in a self-assessment. View Image Martin Lewis urges UK households to 'call HMRC' for a new tax codeMartin Lewis has urged taxpayers to call HMRC for a new tax code to solve an issue. ‌He said: “There are many people out there with Child Benefit who are on the Higher Income Child Benefit Charge. It's still worth getting it with an income under £80,000, the big problem is administratively you had to fill in a self-assessment tax form. Article continues belowIf you usually submit a self-assessment tax return then you’ll need to reclaim the High Income Child Benefit Charge as part of your self-assessment.