Net measure, tax applied cleanly
A valuation is a measure of work, not a tax return. QScope keeps the measure net and applies VAT, the reverse charge and CIS as a separate layer, so neither corrupts the other.
QScope Team · 14 January 2026 · 6 min read
On a UK job the certified valuation is a measure of work done. What is actually paid, and by whom to whom, then passes through VAT, the domestic reverse charge for construction services and the Construction Industry Scheme. QScope keeps these as separate layers, because the moment tax logic bleeds into the measure, the valuation stops reconciling.
Net first, always
Every line in a QScope valuation is net. Measured work, variations, materials on site, retention: all calculated before any tax treatment. This is not a preference, it is what makes the numbers auditable. The gross valuation reconciles to the bill and the variation register at the net level, and tax is applied to a figure that has already been agreed.
VAT at twenty per cent
Standard rated construction work carries VAT at twenty per cent. QScope applies it to the net certified sum, so the tax follows the agreed measure rather than being embedded in individual rates where it cannot be checked.
The domestic reverse charge for construction services
Since March 2021 the VAT domestic reverse charge applies to most construction services between VAT registered businesses in the supply chain. The customer accounts for the VAT rather than the supplier charging it. QScope flags where the reverse charge applies so the payment document states that the customer accounts for the VAT, rather than showing a VAT amount the supplier is not collecting.
CIS deductions
Under the Construction Industry Scheme a contractor deducts from a subcontractor's payment and passes it to HMRC. The deduction applies to the labour element, not to materials, and not to VAT. QScope holds the CIS position on the payment so the deduction comes off the right base, and the net measure of work is never touched by it.
Why the layering matters
A valuation that has VAT and CIS baked into its rates cannot be reconciled, cannot be remeasured cleanly, and cannot survive a variation without a rebuild. QScope's separation means the surveyor argues about the measure, the tax layer follows automatically, and a change to one does not silently corrupt the other. Net work up, tax on top, deductions on the payment. Three layers, kept apart on purpose.
QScope values the work net, then applies VAT at twenty per cent, the construction reverse charge and CIS deductions on the payment, keeping the measure and the tax treatment as separate layers.