Self-Billing Explained — When the Customer Raises Your Invoice (2026)

What Is Self-Billing?

Self-billing is an arrangement where the customer (the buyer of your work) prepares the supplier's invoice and sends it to the supplier, usually with the payment, instead of the supplier issuing the invoice themselves. In a normal sale, you do the work and send the customer a bill. Under self-billing, the relationship is flipped: the customer works out what they owe you, produces the invoice in your name, and pays it.

It is widespread wherever one business engages a large number of subcontractors and wants to control the paperwork. A main contractor on a housing development, a national housebuilder, or a labour agency placing trades on site will often run self-billing across all their subbies. From their side it keeps the format consistent, lets them reconcile against their own records, and — crucially in construction — lets them apply the right CIS deduction at the point they raise the document.

For you as the subcontractor, it can feel like the admin has been taken off your hands. That's genuinely a benefit. But the trade-off is that you lose direct control over how your sale is documented, and you have to police the figures that someone else has produced.

The VAT Rules You Must Know

HMRC allows self-billing, but only if specific conditions are met. Get these wrong and either you or your customer can end up accounting for VAT incorrectly — sometimes twice over. Here are the rules that matter for a VAT-registered subcontractor.

There must be a signed self-billing agreement

Before any self-billed invoice can be raised, there has to be a written, signed self-billing agreement between the two parties. Both parties normally need to be VAT registered for the customer to issue a self-billed VAT invoice that you can both rely on. The agreement records that you accept invoices the customer raises on your behalf, and that you will not issue your own VAT invoices for the same supplies.

The agreement must be reviewed and renewed

A self-billing agreement is not a one-off you sign and forget. It must be reviewed at set intervals — normally every 12 months — and renewed. Where an agreement has no fixed expiry date, the customer must periodically check that your VAT details are still valid before continuing to self-bill you. If the agreement lapses without being renewed, the documents the customer raises stop being valid VAT invoices.

The invoice must carry the right wording

A self-billed invoice has to contain all the normal details of a valid VAT invoice — your name, address and VAT number, the customer's details, an invoice number, the date, a description of the work, the net amount, the VAT rate and the VAT amount. On top of that it must clearly carry the words "SELF-BILLING" (or "self-billed invoice") on the face of the document. If that marking is missing, it is not a compliant self-billed invoice.

You must not also issue your own invoice

Once a supply is covered by self-billing, you must not raise your own VAT invoice for the same work. If you do, both documents are floating around for one supply and VAT can end up accounted for twice — a mess that takes time and money to unwind. Let the self-bill be the single record of that sale.

You must tell the customer about VAT changes immediately

If your VAT status changes, the customer needs to know straight away so they raise the documents correctly. In particular, you must tell the customer immediately if you deregister from VAT or if your VAT registration number changes. They are relying on your details to produce valid invoices; out-of-date details mean invalid VAT documents.

Self-Billing VAT Rules at a Glance

Pros and Cons for the Subcontractor

Self-billing genuinely cuts both ways. Whether it works in your favour depends partly on how well-organised the customer is.

The upsides

• The paperwork is done for you. You don't have to chase measurements, work out the VAT and raise an invoice — the customer produces it.
• Often faster payment. Because the customer raises the document on their own schedule and pays against it, you frequently get paid sooner and without an invoice-chasing cycle.
• Consistent format. Every self-bill from that customer looks the same, which can make your own bookkeeping more predictable.

The downsides

• Loss of control. You are no longer the one deciding what the invoice says — amounts, dates and descriptions are set by someone else.
• Risk if the customer gets it wrong. If they apply the wrong VAT treatment, miss the reverse charge, or deduct the wrong amount of CIS, the error lands on documents in your name — and you still have to fix your own VAT position.
• You must stay on top of it. Self-billing only saves you admin if you trust the figures; in practice you have to check every self-bill rather than file it blindly.

How Self-Billing Interacts With CIS

In construction, self-billing and the Construction Industry Scheme almost always travel together. When a contractor self-bills a subcontractor, the self-bill typically shows the CIS deduction taken from the labour element. So a single document will set out the gross value of the work, the materials, the labour the deduction is calculated on, and the CIS withheld at 20% (registered subcontractor) or 30% (unverified).

This is one reason main contractors like self-billing: they verify you with HMRC, apply the correct deduction rate, and produce a document that already reflects it — rather than receiving an invoice from you and adjusting it. The amount of CIS shown on the self-bill is what you reconcile against your CIS records and, if you're a limited company, offset against your PAYE liabilities. Check it: a wrong verification status or rate on the self-bill directly affects how much cash you receive now and how much sits with HMRC until your return.

Self-Billing and the VAT Domestic Reverse Charge

The other piece that catches subcontractors out is the VAT domestic reverse charge for construction services. Where the reverse charge applies to your supply — broadly, construction work between VAT-registered businesses that falls within CIS, where the customer is not the end user — you do not charge VAT on the sale. Instead the customer accounts for both the output and input VAT on their own return.

When that supply is self-billed, the self-bill must reflect the reverse charge: no VAT is added to the amount, and the document should state that the reverse charge applies and show how much VAT the customer must account for. If you see a self-bill that adds 20% VAT to work that should have been reverse-charged, that's a red flag — VAT has been charged that shouldn't have been, and it needs correcting before it feeds into anyone's return.

Checking Your Self-Bills Are Correct

Here is the point that matters most: handing the invoicing to your customer does not hand them responsibility for your VAT. You remain responsible for the figures on your own VAT return. If a self-bill is wrong and you submit a return based on it, the error is yours to put right with HMRC. So treat every self-bill as something to verify, not just file.

Run a quick check on each one:

• Right VAT rate. Standard-rated, reverse charge, or otherwise — does the treatment match the work you actually did?
• Right amounts. Net value, materials, labour and totals should match the job and your records.
• Reverse charge handled properly. If the supply is reverse-charge, no VAT should be added and the document should say so.
• CIS deduction correct. The right rate (20% or 30%) applied to the right labour figure.
• Valid VAT invoice details. Your correct VAT number, an invoice number, the date, and the "self-billed invoice" wording all present.

What to Do if a Self-Bill Is Wrong

Don't just amend it yourself and don't raise your own invoice to "correct" it — that risks double-counting the VAT. Because the customer raised the document, the customer issues the corrected version. So:

• Flag it promptly. Contact the customer as soon as you spot the error and explain exactly what's wrong — wrong rate, missing reverse charge, wrong CIS deduction, wrong amount.
• Ask them to reissue. The customer should raise a corrected self-bill (or a credit and a fresh one) so the record matches reality.
• Hold the return until it's right. Where you can, make sure your VAT return reflects the corrected figures rather than the faulty self-bill.
• Keep the trail. Retain both the original and the corrected document and a note of what was changed.

Record-Keeping

Self-bills are your VAT records just as much as invoices you raise yourself, and the same retention rules apply. Keep every self-billed invoice you receive, along with the signed self-billing agreement and evidence of each review or renewal. Store them alongside your other VAT and CIS paperwork so that, at the end of a quarter, you can reconcile what the customer self-billed against the work you actually did and the deductions you expect.

The practical habit that keeps subcontractors safe is simple: log each self-bill as it arrives, check the five points above, and only then treat it as settled. That way the time self-billing saves you on raising invoices isn't lost to untangling VAT and CIS errors months later.