KSA e-invoicing: clearance is the rule, and the waves keep coming.
Under ZATCA's FATOORA system, a Phase 2 invoice is not valid until the authority has cleared and stamped it. Wave 24 — effectively every remaining VAT registrant above SAR 375,000 — must integrate by 30 June 2026. This guide covers how the clearance model works, which wave you are in, and why waiting for your notification letter is the most expensive strategy available.
From generation to full integration.
FATOORA arrived in two phases. Phase 1 standardised invoice generation; Phase 2 wired every taxpayer's system into ZATCA's platform, wave by wave, working down the revenue ladder.
- December 2021 — Phase 1 Generation phase live. All VAT registrants issue structured electronic invoices from compliant systems — no more handwritten or unstructured invoices.
- 31 March 2026 — Wave 23 deadline Taxpayers with VAT revenues above SAR 750,000 in 2022, 2023 or 2024 integrate with FATOORA for clearance.
- 30 June 2026 — Wave 24 deadline Taxpayers with VAT revenues above SAR 375,000 in 2022, 2023 or 2024 — effectively all remaining VAT registrants of any substance — integrate with FATOORA.
- After June 2026 — awaiting announcement No Wave 25 has been announced as of June 2026. Taxpayers below the Wave 24 threshold await notification. ZATCA's pattern has been to give roughly six months between the wave letter and the integration deadline.
Who must do what, when.
Every VAT registrant in the Kingdom has been on Phase 1 since December 2021. Phase 2 is the harder step: your invoicing system must talk to ZATCA's platform in real time, because under the clearance model a standard tax invoice is not valid until ZATCA has cleared and cryptographically stamped it.
If your VAT revenues exceeded SAR 750,000 in 2022, 2023 or 2024, you were Wave 23 — the integration deadline was 31 March 2026. If they exceeded SAR 375,000 in any of those years, you are Wave 24, and your deadline is 30 June 2026. That threshold is low enough that Wave 24 effectively sweeps in every remaining VAT registrant of substance.
If you fall below the Wave 24 threshold, no wave has been announced for you as of June 2026. That is not a reprieve; it is a queue. Wave letters have arrived with roughly six months' notice, and six months is a tight window for ERP integration, certificate onboarding, and clearance testing — especially when an entire wave of taxpayers is competing for the same implementation capacity at once.
The scale of the system is its own argument for taking validation seriously: ZATCA reportedly processed around 8.2 billion invoices in 2025. At that volume, the platform's rejection rules are exercised constantly — and rejected invoices are invalid invoices.
- Clearance: standard tax invoices go to ZATCA in real time and return stamped — only then are they valid
- Wave assignment: by VAT revenues in 2022, 2023 or 2024 — check all three years, not just the latest
- Notice period: wave letters have arrived roughly six months before the deadline
- Wave 24: above SAR 375,000 — integrate by 30 June 2026
Six things to do before your wave letter arrives.
- 01Check your wave status against all three reference years. Wave assignment looks at VAT revenues in 2022, 2023 or 2024 — exceeding the threshold in any one of them puts you in scope. A single strong year is enough.
- 02Do not wait for the letter. ZATCA's wave notifications have given roughly six months' notice. Integration, testing, and certificate onboarding comfortably consume that window — starting at the letter means finishing at the deadline, with no slack for surprises.
- 03Verify your Phase 1 compliance is actually solid. Phase 2 builds on Phase 1 generation requirements. Gaps that went unnoticed since December 2021 — QR codes, mandatory fields, archiving — surface abruptly when clearance validation begins.
- 04Clean your master data before you integrate. VAT numbers, buyer details, and tax codes drive clearance rejections. Every rejection is an invoice your customer cannot legally process — fix the masters before they become a production incident.
- 05Plan the cutover with your ERP vendor early. Each wave deadline concentrates demand on the same pool of integrators and vendor resources. Booking implementation capacity late is how six-month windows become impossible.
- 06Build rejection handling into daily operations. Under clearance, a rejected invoice is not a warning — it is a document that does not legally exist. Someone needs to own the rejection queue from day one, with a defined fix-and-resubmit procedure.
Integration work, done by people who have shipped it.
For KSA clients, ClayDesk delivers the Phase 2 integration path end to end: wave determination against the three reference years, ERP field mapping to the FATOORA XML requirements, clearance testing, and rejection-handling procedures that treat the rejection queue as an operational workflow rather than an afterthought. Master-data remediation comes first, because that is where clearance failures actually originate.
For groups operating in both KSA and the UAE, we build one architecture with two activations — Saudi clearance and UAE five-corner Peppol consuming the same validated master data through the same integration layer. Delivery model, timelines, and engagement tiers are on the e-invoicing practice page.
Asked on most KSA discovery calls.
We have not received a wave letter. Are we safe to wait?
Waiting is the riskiest option on the table. Wave letters have arrived with roughly six months' notice, and that window has to absorb ERP integration, certificate onboarding, clearance testing, and master-data fixes — while every other taxpayer in your wave competes for the same implementation capacity. The work done before the letter is the work that makes the deadline comfortable.
What is the difference between Phase 1 and Phase 2?
Phase 1 (generation), live since December 2021, requires invoices to be produced electronically from a compliant system. Phase 2 (integration) connects that system to ZATCA's FATOORA platform: standard tax invoices are cleared and stamped by ZATCA before they are valid. Phase 1 changed how you create invoices; Phase 2 changes whether they count.
Which wave are we in?
It depends on your VAT revenues in 2022, 2023 or 2024. Above SAR 750,000 in any of those years was Wave 23, with a deadline of 31 March 2026. Above SAR 375,000 is Wave 24, with a deadline of 30 June 2026. Below that, no wave has been announced as of June 2026 — you are in the queue, not off the hook.
Our invoices keep getting rejected. Is that an integration problem?
Usually it is a data problem wearing an integration costume. Clearance rejections overwhelmingly trace to master data — wrong or missing VAT numbers, malformed buyer details, inconsistent tax codes. The rejection log is effectively a free audit of your master data; treating each rejection as a one-off resubmission means paying for the same defect repeatedly.
We operate in KSA and the UAE. Is that two separate projects?
One architecture, two activations. Saudi Arabia runs a clearance model and the UAE a five-corner Peppol exchange model, but both consume the same validated master data through the same integration layer. Building them as unrelated projects means paying for the foundation twice.
Related thinking.
Wave 24 deadline, or waiting for your letter?
Tell us your VAT revenue band, your ERP, and your invoice volume. We confirm your wave, your deadline, and what integration will cost — with a written fixed-fee quote within 24 hours.