Taxes Management Act 1970 section Schedule 1AB paragraph 3

Making a claim

Section Schedule 1AB paragraph 3 sets out the time limit for making a claim to recover overpaid income tax or capital gains tax, and specifies how the relevant tax year is determined depending on the nature of the overpayment.

• A claim must be made within 4 years after the end of the relevant tax year.
• Where tax has been overpaid due to a mistake in a tax return, the relevant tax year is the year to which the return (or the first return, if more than one) relates.
• Where the overpayment is not linked to a return mistake, the relevant tax year is either the year for which the payment was made (if tax was actually overpaid) or the year to which the assessment, determination or direction relates (if tax was over-assessed but not yet paid).
• A claim under this provision must be made as a standalone claim and cannot be included within a self-assessment tax return.