HMRC may have overcharged 107,000 taxpayers last year

• HMRC is set to review 107,000 tax cases from the 2025-26 tax year following complaints over a technical system error that could leave taxpayers overcharged.
• The ordering glitch in the tax system incorrectly calculates tax-free allowances, including personal, dividend, and savings allowances, resulting in higher bills.
• Although the issue was first acknowledged by the tax authority in 2021, the system error persists and requires manual checks to adjust affected calculations.
• HMRC expects the number of calculations requiring manual review to fall to around 20,000 next year as tax rules and rates change.
• Tax experts have criticised the ongoing flaw, saying that any overcharged amount is significant to individual taxpayers, regardless of the sum.

IN FULL

HMRC to review over 100,000 tax bills after complaints of overcharging