You must submit your VAT431C claim to HMRC within 6 months of the date of the completion certificate — not 6 months from when you move in, and not 6 months from when building work stops. The completion certificate is issued by your local authority building control team after they are satisfied the works comply with Building Regulations. Missing the 6-month window means your claim is permanently lost — HMRC has no discretion to accept late claims.
HMRC's VAT431C deadline is absolute. There is no appeal process, no hardship exception, and no HMRC discretion once the window closes. A claim worth £25,000 in reclaimable VAT becomes £0 if submitted one day late.
The 6-month window begins on the date your local authority building control inspector issues a completion certificate (or a final certificate under an Approved Inspector scheme). This is the trigger date — not completion of works or practical completion.
When your contractor issues a practical completion certificate or final account, that is not the VAT431C deadline trigger. You need the building control completion certificate.
Moving into the property does not start the clock. However, if you move in before a completion certificate is issued, you should apply for the certificate promptly — delays in obtaining it risk the deadline coinciding with invoice collection.
HMRC does not accept VAT431C claims submitted after the 6-month deadline. There is no HMRC discretion, no appeal route, and no alternative scheme to use instead.
VATBuild is not affiliated with HMRC. References to HMRC publications are for informational purposes. Always consult a qualified tax adviser before submitting a reclaim.
VATBuild tracks your project's completion status and flags when a completion certificate date has been entered. It calculates your VAT431C deadline and displays it prominently — and it identifies any outstanding invoice issues (missing VAT numbers, rate errors, unresolved line items) before your deadline arrives, so you submit a complete and accurate claim.