You finish a phase of work on a Thursday, the report is signed off, and the natural next move is to write an invoice and email it. If your client is a Saudi company, that is the one thing you cannot do. The invoice goes to the Authority before it goes to the client, and it carries what a fee note never did: the client's VAT number and address, your own address in six elements, and a signature no word processor can produce.
Almost everything you issue is a standard invoice
A simplified invoice is for consumers: you hand it over immediately and report it within 24 hours. A standard invoice is for a VAT-registered business or a government body, and it must be cleared before you share it with the buyer. Consultants, agencies, design studios, training providers, technical services — your clients are companies, so near enough everything you issue is standard. The full comparison is here; the consequence is short: issue and send are no longer one moment.
Clearance is an automated call made at the moment you issue, not an approval queue you sit in. Two things can come back. A rejection means the invoice failed a rule and does not exist until you fix it and re-send. A warning means the Authority accepted the invoice and flagged something anyway. The error codes guide covers both. BR-KSA-09, the seller address, is the one new sellers meet earliest, and it is a warning rather than a rejection: your invoices keep clearing while the address carried over from a commercial registration is still missing the district and building number the national address expects. Nothing forces you to fix it, which is exactly why it goes unfixed for a year.
The sequence, proposal to payment
- Proposal or quotation. Not a tax document: no VAT due, no clearance. Give it a validity date and get it accepted in writing.
- Purchase order. If the client raises one, get the number before you start; their accounts department will look for it on the invoice.
- Work, delivered and signed off. Acceptance turns effort into a supply you can bill.
- Invoice, cleared. Signed XML to the Authority, cleared document back, then to the client.
- Payment, on whatever terms the contract set. Recorded against the invoice, because part-payments are normal.
The tax falls due before the client pays
VAT becomes due at the earlier of three events: the supply, the invoice, or the payment. For a project firm the invoice is almost always the earliest, so the VAT belongs to the period in which you invoiced — not the one in which you were paid.
Run the arithmetic once and you will not forget it. Take a 200,000 SAR project billed at the standard rate published at zatca.gov.sa — 30,000 SAR of VAT — with the client paying on 90-day terms. The VAT falls due long before the 230,000 SAR arrives, out of your own working capital. Three such projects overlapping, and a firm with a healthy order book cannot make payroll.
The tax point is what it is; the fixes are unglamorous. Invoice early in a period rather than late where the contract allows, bill milestones rather than one lump at handover, and always know which invoices are unpaid.
Retainers and milestones
A retainer paid in advance flips the order: the payment is now the earliest event, so the tax point is the day the money lands. Invoice it then, not at the end of the engagement.
Milestone billing is several standard invoices instead of one, each cleared on its own, each carrying its own counter and hash link to the invoice before it, each naming the milestone rather than repeating "professional services".
Scope changes are notes, not edits
A signed and transmitted invoice is immutable: you cannot correct a number in it and you cannot delete it. Approved extra scope on an already-invoiced amount is a debit note (383); a reduction, a late discount or a cancelled phase is a credit note (381). Both carry a reason and a reference to the original invoice. Work never invoiced is not a note — it is the next invoice.
Rebilled expenses go on as their own lines, described for what they are, never buried in the fee. Whether a cost is a recharge you add VAT to or a pass-through you do not depends on whose name the supplier invoice carries — a question for your accountant.
What the invoice must carry, and what firms actually send
| Required on a standard tax invoice | What a typical firm's PDF has |
|---|---|
| Your VAT number and national address in six elements: street, building number, district, city, postal code, country | A letterhead with a PO Box |
| The client's VAT registration number | The client's trading name |
| The client's address: street, city, country code | Nothing, or a city |
| Each line with description, quantity, unit price and its VAT | One line: "Consultancy services" |
| Total excluding VAT, VAT amount, total including VAT | A single total |
| An incrementing counter and the previous invoice's hash | A number from a spreadsheet, sometimes reused |
| A compliant QR code and a digital signature | A logo and a scanned signature image |
| Cleared by the Authority before sending | Emailed the minute it was written |
| The signed XML kept six years | A PDF in a folder |
Why accounts payable parks an invoice
- No purchase order number, or the wrong one.
- A legal entity name that does not match the contract — a branch, a trading name, an old one.
- One undifferentiated line nobody can match to a deliverable or a rate card.
- Rebilled expenses with no receipts attached.
- Totals that stop adding up once a discount is applied.
- A missing or invalid VAT number on either side. Check the client's with the VAT number lookup first.
None of these are ZATCA problems. The Authority can clear an invoice that a finance department then sits on for weeks, and on a project firm's cash flow that delay costs more than the compliance did.
What this needs from a system
Less than people assume: something that issues a standard invoice, clears it, keeps the signed XML and tells you what is unpaid. That is not a general ledger, and it replaces no accountant.
ZATCA Tools does that narrow job. Connecting takes one OTP from the Fatoora portal and a few minutes. Invoices are signed with their QR code and cleared before you send them, rejections come back with the official ZATCA code and a link to its guide, and the signed XML is archived six years and downloadable. Quotations use QT- numbering with a validity date and a share link the client can accept; an accepted one becomes an invoice draft. Receipt vouchers use RV- numbering, so each invoice reads paid, partially paid or unpaid, and per-customer statements show what is outstanding. It is not an accounting system: no ledger, no journals, no inventory, no payroll. Already running an ERP? Connecting it through the API is the smaller change. Free during the launch period — start here, or read the Phase 2 walkthrough.