HMRC Error Costs 8.7 Million Pensioners £43.5m in Overpaid Tax

It’s a headache no one wants, especially when you’re on a fixed income. Up to 8.7 million UK pensioners have been quietly overcharged for their income tax due to a glitch at HM Revenue and Customs. The blunder? A failure to correctly update the state pension figure in their systems after the annual "triple lock" increase kicked in.

The scale of the error is staggering. While the average overcharge per person is a modest £5, the cumulative effect amounts to roughly £43.5 million collected in error over the last year. It’s not just a rounding error; it’s a systemic miss that has left millions checking their bank accounts with a furrowed brow.

The Triple Lock Glitch Explained

Here’s the thing: the government guarantees the state pension rises by the highest of three measures—average earnings growth, inflation, or 2.5%. This is the famous triple lock. For the 2025/26 tax year, the full new state pension jumped from £221.20 to £230.25 per week. That’s an increase of £9.05.

Oddly enough, HMRC’s tax calculation systems didn’t get the memo properly. Instead of using the correct, lower taxable income baseline, the system effectively recorded the pension as being higher than it should have been for assessment purposes. Turns out, this small discrepancy in weekly figures snowballed into significant tax liabilities for those above the personal allowance threshold.

If you’re a basic-rate taxpayer, that tiny error meant paying an extra £1.81. For higher-rate taxpayers, it was £3.62. Additional-rate taxpayers saw a hike of £4. When you average these out across the millions affected, you get that £5 figure. It sounds negligible until you multiply it by 8.7 million people.

Who Is Affected?

This isn’t limited to just one group. The error impacted pensioners who pay tax through two main channels:

• Self-Assessment filers: Those who declare their own income annually.
• PAYE contributors: Pensioners still working or receiving pensions where tax is deducted at source.

The twist is that if your total income falls below your Personal Allowance (currently £12,570), you typically don’t pay income tax anyway. So, while 8.7 million were technically "affected" by the data error, only those whose total income pushed them into the taxable bracket actually lost money. Still, that’s a massive chunk of the retired population.

HMRC’s Response and the Fix

Has anyone taken responsibility? Yes. HM Revenue and Customs has acknowledged the mistake. An unnamed spokesperson told The Independent: "We apologise to those affected by this error and are working at pace to fix the issue, although the impact is small with the difference in tax owed being around £5 in most cases."

Note the wording: "working at pace." They’ve been trying to patch this since last year. The plan? A technical fix later this summer. No specific date has been given, which is frustrating for those waiting for refunds. But wait—refunds aren’t automatic yet. You’ll likely need to claim them back once the system is corrected.

A Broader Pattern of Errors?

This incident feels less like an isolated glitch and more like a symptom of a larger problem. Financial expert Martin Lewis, host of Money Show Live, has been sounding the alarm recently. He warned viewers that "millions of tax codes are wrong" and urged everyone to check their status. Lewis isn’t talking about just this pension error; he’s highlighting a widespread issue.

Data supports his concern. According to Pie.tax, which analyzed data from an official information request, tax code errors caused 5.6 million people across the UK to overpay a combined £3.47 billion in the 2023–24 tax year alone. These weren’t just pensioners; workers were hit too. The causes range from administrative lapses to employer payroll mistakes and sheer complexity in the tax code.

So, while the £43.5 million pension blunder is fresh news, it sits atop a mountain of previous overpayments. It raises a valid question: why does it take years to fix these things?

What Should You Do Now?

Don’t panic, but do pay attention. If you’re a pensioner and suspect you’ve been overcharged, keep an eye on your tax codes. HMRC will eventually roll out the fix, but proactive checks can save you money in the long run. Use the online HMRC service to view your tax code certificate. If it looks off, call them. It’s tedious, sure, but your wallet will thank you.

For now, we wait for that summer fix. Until then, millions of retirees are left wondering if that extra £5 is coming back—and if it’s worth the hassle of chasing it. In the world of bureaucracy, sometimes the answer is yes.