Martin Lewis tax code advice as HMRC owes average £689 to millions

Martin Lewis tax code advice as HMRC owes average £689 to millionsYou need to check as no-one else will do it for youCommentsMoneyNeil Shaw Assistant Editor (Money and Lifestyle)07:51, 22 Apr 2026Updated 07:55, 22 Apr 2026View 2 ImagesMartin Lewis has issued advice for April changesMillions of UK workers and pensioners could be paying more tax than they owe — and most have no idea it is happening, according to money saving expert Martin Lewis. Writing as part of his new tax year guidance for April, Martin issued an urgent reminder to anyone in employment or receiving a pension: "Millions of codes are wrong each year, so it's crucial to check yours — it's your responsibility, not your employer's, not HMRC's." He warned on his BBC Sounds podcast: "Do not assume that because it's coming from HMRC that it is right. Millions — and that is not an exaggeration, it's a literal fact — millions are wrong every year." The scale of the problem is significant. According to a Freedom of Information request submitted by accountancy firm UHY Hacker Young, 5.6 million people overpaid a combined £3.5 billion in income tax in the most recent tax year, with the average overpayment standing at around £689. HMRC paid around £3 billion back to 4.2 million people who had overpaid in the 2024/25 tax year alone, according to MoneySavingExpert's own FOI data — but crucially, HMRC is under no legal obligation to notify individuals of overpayments or issue refunds automatically.‌View 2 ImagesHMRC could owe you a lot of moneyA tax code is the series of numbers and letters on a payslip that tells an employer or pension provider how much income tax to deduct. The most common code for the 2026/27 tax year is 1257L, which reflects the standard £12,570 personal allowance. If yours looks different and you are unsure why, it is worth checking. Errors are most likely to creep in after a life change. Lewis has flagged the most common triggers — start...