If you underpaid duty or import VAT, tell HMRC through the online voluntary clearance amendment service (C2001). HMRC then raises a C18 demand for the extra amount. If you used postponed VAT accounting, correct the import VAT on your VAT return instead.
If you overpaid and the declaration was made in the Customs Declaration Service, claim through that service using your EORI number. Most overpayment claims must be made within three years. You need a commercial invoice showing the correct value and the amount that should have been paid, and a packing list and transport documents can support the claim.
VAT-registered importers cannot reclaim overpaid import VAT this way. Reduce the output tax in box 1 of the VAT return instead. Repayments are only made to a UK bank account.
Sources
- GOV.UK: Apply for a voluntary clearance amendment for an underpayment (C2001) (opens in a new tab)
- GOV.UK: How to claim a repayment of import duty and VAT if you've overpaid (opens in a new tab)
A summary of the public sources above, checked when it was published. General information, not legal, tax or financial advice.