Overview
- Official HMRC figures show about 730,000 tax refunds went unclaimed last year, worth an average £855 each from a £624 million pot.
- A separate FOI by UHY Hacker Young reports 5.6 million people overpaid a total of £3.5 billion in the most recent tax year, averaging about £689.
- Refunds are not automatic, so people must review their tax code and any P800 letter, with Martin Lewis warning that millions of codes are wrong each year.
- The simplest route is to claim through the HMRC app or online bank transfer, with most repayments arriving in about five working days, while cheques can take up to six weeks.
- Common causes include outdated tax codes, payroll mistakes, job or hours changes, multiple income sources, or starting a pension, and claims can be backdated up to four years while employers cannot claim on an employee’s behalf.