What's included
Per payment, not per job
The deduction applies to the labour element of each payment as it is made. A 30% deposit does not attract 20% of the whole job's labour.
Labour and materials split
Every stage raises separate labour and materials lines, so the deduction lands on the right half without special-casing.
All three rates
Gross at 0%, net at 20%, unverified at 30%, applied to the subcontractor as HMRC verified them.
VAT domestic reverse charge
Applied where the supply qualifies, with the wording the invoice is required to carry.
Visible on the invoice
The deduction is shown as a line the subcontractor can reconcile, not folded silently into a total.
Refuses rather than guesses
If the contract value cannot be established, a staged invoice will not be raised. A nil invoice raised quietly is the worst outcome on a money feature.
CIS & VAT Reverse Charge for Construction — your questions
Why does per payment versus per job matter?
Because getting it wrong is an HMRC error in a direction that hurts someone. Over-deduct and the subcontractor is short and reclaiming; under-deduct and the contractor carries the shortfall. It is taken on the labour inside each payment, not once on the whole contract.
Do you file my CIS return?
No. ServicePay calculates and records the deduction and shows it on the invoice. Filing remains between you and HMRC or your accountant.
What about the reverse charge?
Where the supply is within the scope of the domestic reverse charge for construction, the invoice is prepared on that basis with the required wording, and the VAT is not charged to the customer.