The period just before completion is your last chance to fix VAT problems at source. Once your building control certificate is issued, the 6-month VAT431C deadline starts. Any contractor invoice showing 20% VAT on services instead of 5% becomes much harder to correct after the project ends and the contractor moves on. Use the time before completion to audit every invoice, identify errors, and request corrected documents.
After your completion certificate is issued, you have exactly 6 months to prepare and submit your VAT431C claim. Getting to that moment with missing invoices, uncorrected rate errors and unresolved disputes can turn a £25,000 reclaim into a fraction of that — or a rejected claim.
Check every contractor invoice for the correct 5% VAT rate. Flag any showing 20% and contact the contractor for a corrected invoice while the relationship is still active.
Identify any invoices or receipts that are missing, and contact suppliers now. Obtaining duplicate invoices is far easier while the project is live than six months after completion.
Asking a contractor to reissue an invoice after they have been paid and moved on is difficult. Many are unresponsive. Corrections become harder, not easier, with time.
Builders' merchants may have limited records beyond 12 months. Till receipts fade. Online accounts may be closed. The longer you wait, the harder it is to recover missing documentation.
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 is designed to be used throughout the project, not just at the end. It tracks every invoice as it arrives, flags rate errors immediately, and identifies missing documents before the completion deadline arrives. For projects approaching completion, VATBuild provides a full pre-claim readiness check — showing exactly what is resolved, what needs action, and what the current provisional claim value is.