HMRC is advising numerous taxpayers to verify if they are eligible for a tax refund, with an average refund amount of £473. One common reason for potential overpayment is being placed on an incorrect tax code, especially after a job change.

For the current tax year, the prevalent tax code is 1257L, applicable to individuals with a single job or pension. This code allows earnings of £12,570 without taxation, matching the current personal allowance. Overpaid taxes can also stem from errors like improper splitting of personal allowances for those with multiple jobs or incorrect pension income tax deductions.

HMRC estimates sending about four million P800 tax refund letters between June and August. In a recent announcement on X (formerly Twitter), HMRC encourages individuals to investigate if they are entitled to a refund, mentioning a potential average refund of £473.

To check your tax code, refer to your latest payslip, P45 (if recently unemployed), or GOV.UK with a Government Gateway ID. Individuals can claim refunds online through GOV.UK using the reference number on the P800 letter and their National Insurance number, with the possibility to claim back up to four previous tax years for incorrect tax codes. HMRC may extend this period under certain circumstances where they are at fault for the overpayment.

MoneySavingExpert.com cautions against scammers impersonating HMRC, emphasizing that HMRC communicates about tax refunds exclusively through letters, not via text, email, or phone calls.