VAT errors are not limited to an incorrect percentage. They more often arise when one schedule is read as VAT-inclusive while another expects values excluding VAT.
Read every pricing heading
Mark whether rates, totals and reimbursables are stated as inclusive or exclusive. Do not infer the basis from a familiar template; use the wording in the issued pack.
Test linked totals
Trace the VAT amount into the summary and form of offer. If the bidder is not VAT-registered, obtain appropriate internal or professional guidance rather than simply deleting the line.
Examine allowances and fees
Provisional sums, disbursements and management fees may have tender-specific treatment. Confirm whether a percentage is applied before or after tax and whether that sequence is visible in the returnable.
Preserve the approved basis
When correcting a mismatch, update every linked document. A revised summary with an unchanged declaration can leave the submission internally inconsistent even though the arithmetic now works.