Reverse Charge, Straight Talk: VAT on Subcontractor Invoices Without the Guesswork

You finish a decent week on site, send off your invoice, and then the main contractor's accounts team emails back: “Can you reissue without VAT? Reverse charge applies.” Or worse, they pay you the gross amount and tell you to “sort the VAT out later.” Either way, your tidy invoice has just turned into a paperwork problem.

The domestic reverse charge for construction services has been with us since 1 March 2021. It is not a temporary COVID-era quirk or a niche VAT wheeze. For plenty of subcontractors in 2026, it is simply how invoices work. Yet it remains one of the easiest things to get wrong, especially when CIS deductions, materials and retention are all swimming around on the same page.

This is not a tax textbook. It is a site-level guide to keeping your invoices clean, your cash flow predictable and HMRC off your back.

The 30-second version

Under the domestic reverse charge, a VAT-registered subcontractor does not charge VAT to a VAT-registered main contractor for certain construction services. Instead, the main contractor accounts for the VAT on their own VAT return. The subcontractor invoices the net amount and notes that the reverse charge applies.

That means the subcontractor is not handing over VAT to HMRC on that job, and the main contractor is not paying VAT to the subcontractor. The main contractor still has to deal with the VAT accounting, usually as both output tax and input tax, depending on their own VAT position.

For the subcontractor, the practical effect is simple: your invoice is net. Do not add 20% just because that is what you have always done. Do not treat the absence of VAT as a discount either. Your price should already reflect the net amount you expect to be paid.

Which jobs are caught?

The reverse charge generally applies when all of these are true:

• You are VAT-registered and making a supply of construction services.
• The work is within the scope of the Construction Industry Scheme, or closely related to it.
• Your customer is VAT-registered and is a main contractor, not the end user.
• The customer is not an intermediary connected to an end user.
• The customer is buying the services for their business, not as a private individual.

That last point matters. If you are doing work for a homeowner, a landlord buying for their own property, or another end user who is not going to onward supply construction services, the reverse charge normally does not apply. You charge VAT in the usual way.

It is also not about the size of the job. A small repair can be caught if it is construction work under CIS and the customer is a main contractor. Equally, a large job for an end user can sit outside the reverse charge. The test is the status of the customer and the nature of the supply, not the invoice value.

If you are unsure, ask the customer in writing whether they are an end user, intermediary or main contractor for this project. Keep the reply. A quick email trail is worth more than a heated phone call six months later.

What a compliant invoice should say

A reverse-charge invoice does not need to be a work of art, but it does need to be obvious. Include:

• Your business name, address and VAT number.
• The customer's name and address.
• A unique invoice number and date.
• A clear description of the work.
• The net amount.
• A statement that the domestic reverse charge applies.
• A reference to section 55A of the VAT Act 1994, which is the usual wording HMRC expects.

A simple line such as “Reverse charge: VAT Act 1994 Section 55A applies” is the kind of thing accounts teams look for. Put it somewhere visible, not buried in a footer next to your bank details.

Do not charge VAT and then write “reverse charge” beside it. That is the invoice equivalent of indicating left and turning right. If VAT is shown, the customer will usually expect to pay it, and your records become messy. If you have already sent one like that, issue a corrected invoice or credit note promptly and explain the correction in writing.

CIS and VAT are not the same deduction

This is where a lot of good builders get tangled. CIS deductions and VAT are separate. CIS is about tax on payments to subcontractors. VAT is about the supply of goods and services.

Under the reverse charge, your invoice is normally net of VAT. The main contractor then applies CIS deductions to the net amount, where applicable. They should not calculate CIS on a VAT figure that should not be there in the first place.

Keep your paperwork clear: labour, materials, plant hire and any other chargeable items should be described properly. If materials are part of the invoice, say so. If retention is being held, show it. The clearer the breakdown, the less chance the accounts team misreads the whole thing and delays payment.

When the main contractor wants to pay the old way

It happens. A main contractor's buyer or site manager tells you to “just add VAT like normal” because their system cannot cope, or because they have decided the reverse charge does not apply. Sometimes they are right. Often they are not.

Do not simply go along with it to keep the peace. If the reverse charge applies and you charge VAT, you may end up having to account for VAT you never should have charged, while the customer tries to recover it. That is a recipe for credit notes, amended returns and a strained relationship.

If the customer insists, ask for their VAT number and a written explanation of why they believe the reverse charge does not apply. If they are an end user or intermediary, get that confirmed. If they are a main contractor and the work is within CIS, the reverse charge is likely to be the correct treatment.

If they have already paid you gross, do not treat the VAT element as extra profit. It is not your money. Correct the invoice, repay or credit the VAT as appropriate, and keep a record of what happened. If the amounts are significant, speak to your accountant before you dig a deeper hole.

Protect the cash flow

For subcontractors, the reverse charge can feel like a cash-flow squeeze because there is no VAT to hold temporarily. That is why your pricing needs to be clear from the quote stage. Quote net, state the VAT treatment, and make sure the person signing the order understands what they will actually be invoiced.

For main contractors, the reverse charge is not a reason to slow-pay subcontractors. The VAT accounting happens on the return, but the commercial invoice still needs paying on its agreed terms. A clean reverse-charge invoice should move through the system faster, not slower.

A quick pre-send check

Before you hit send, ask yourself:

• Is the customer a main contractor or an end user?
• Is the work within CIS?
• Have I shown the net amount clearly?
• Have I included the reverse-charge wording?
• Have I avoided charging VAT when I should not?
• Are CIS deductions and materials shown clearly?
• Have I kept a record of any customer confirmation about their status?

Five minutes of checking beats five months of sorting out a VAT mess. The reverse charge is not there to trip you up. It is there to change who accounts for the VAT. Get the invoice right and it becomes routine. Get it wrong and it will quietly eat your margin, your time and your patience.