Home » Free Calculators » VAT Domestic Reverse Charge Calculator

Works out whether a construction supply is invoiced under the VAT domestic reverse charge, normal VAT, or sits outside the reverse-charge legislation, plus the invoice wording and VAT arithmetic for whichever outcome applies.
Answer the six HMRC questions below in order (VAT Act 1994 s55A) for a definitive result on this supply.

Supply
£
Net (VAT-exclusive) value of this supply
Ignored if Q2 is "No" — the rate is then forced to 0%
HMRC Decision Questions (VAT Act 1994 s55A)
CIS construction operations, minus HMRC's exclusions (architects, surveyors, security systems, off-site manufacture)
"No" means zero-rated (e.g. new-build housing) or exempt
Payment for the supply is reported through CIS
Written notification under VATREVCON33100 opts the customer out of the charge
Staff/workers on timesheets (VATREVCON34000): not a labour-only subcontract
Enter the net amount to check the VAT treatment
Per VAT Act 1994 s55A (HMRC VATREVCON manual). Fixed check order: specified service → standard/reduced rated → customer VAT-registered → customer CIS-registered → end-user/intermediary notification → employment business → reverse charge. VAT amount = net × rate; amount payable = net + VAT when VAT is charged, net alone under the reverse charge or a zero-rated/exempt supply.
For guidance only. This tool decides a single supply; always verify with HMRC or your accountant, especially for mixed supplies.

About this VAT domestic reverse charge calculator

This free VAT domestic reverse charge calculator decides how a single construction supply should be invoiced, under the domestic reverse charge (net only), with VAT as normal, or outside the reverse-charge legislation altogether. And gives the invoice wording and VAT arithmetic for whichever outcome applies. It is aimed at construction subcontractors, contractors and their bookkeepers working out whether to charge VAT on a building & construction service, following HMRC’s statutory test under VAT Act 1994 s55A. Answer the six questions in order. Everything runs in your browser. Nothing is uploaded.

How the VAT treatment is decided

The tool follows HMRC’s fixed decision sequence (VAT Act 1994 s55A, VATREVCON manual): specified construction service → standard/reduced rated → customer VAT-registered → customer CIS-registered → end-user/intermediary notification → supplier is an employment business → reverse charge. The first gate that fails fixes the outcome, so it is deterministic even when several would block the charge. A non-specified service or a zero-rated/exempt supply falls outside scope; a customer who is not VAT- or CIS-registered, who has given end-user notification, or a supply of staff by an employment business takes normal VAT; only when all conditions are met does the reverse charge apply. The arithmetic is VAT = net × rate (20% or 5%), with the amount payable being net + VAT when VAT is charged, or the net alone under the reverse charge.

Reviewed by
Managing Director at Ensign Software. Over 20 years working with UK mechanical, electrical, MEP, ductwork and insulation contractors.
Each calculator cites the standard it follows. For design guidance only: always verify the result with a qualified engineer.

Frequently asked questions

What is a “specified” construction service?

It is a CIS construction operation caught by the reverse charge, broadly, on-site construction, alteration, repair and installation work, minus HMRC’s specific exclusions such as architects and surveyors, security-system installation and off-site manufacture. If the supply is not a specified service the reverse charge never applies, and it is invoiced with normal VAT.

What is end-user or intermediary notification?

An end user (who does not on-supply the construction service, e.g. the building’s owner or main contractor selling a finished building) or an intermediary supplier can give the subcontractor written notification that it is an end user or intermediary. That notification (VATREVCON33100) takes the supply out of the reverse charge, so the subcontractor charges VAT in the normal way.

Does it handle mixed supplies and the 5% disregard?

No: the tool decides one supply at a time. HMRC’s 5% disregard lets both parties treat a whole supply as normal VAT when the reverse-charge element is 5% or less, but only if agreed at the start of the contract on overall values, so it is a whole-contract judgement this calculator does not attempt. Always verify with HMRC or your accountant, especially for mixed supplies.

See Ensign in action

Book a free demo and find out how Ensign can save your business time and money.

By completing this form, you are opting in to receive marketing emails from us. You can unsubscribe at any time.