ZATCA Phase 2 Integration for Wave 25: Deadline, Onboarding and Countdown Checklist

ZATCA Phase 2 integration is the requirement to connect your e-invoicing system to ZATCA's Fatoora platform so B2B tax invoices are cleared in real time and B2C simplified invoices are reported within 24 hours. Wave 25 covers resident businesses with VAT-able revenue above SAR 187,500 in any year from 2022 to 2025, with integration due by 1 February 2027.

That leaves roughly 13 weeks from the date of this article. This is a practical action plan for finance directors and business owners in Wave 25: how to confirm you are in scope, what the notification means, how onboarding to Fatoora actually works, a week-by-week countdown and the mistakes that cause last-minute failures. For the full background on Phase 1, invoice types and mandatory fields, read our complete guide to e-invoicing in Saudi Arabia.

What is ZATCA Wave 25?

Wave 25 is the 25th group of taxpayers required to move from Phase 1 (generating compliant electronic invoices) to Phase 2 (integrating with Fatoora). The Zakat, Tax and Customs Authority (ZATCA) announced the criteria on 24 July 2026, and the Governor's Administrative Decision No. 1448-99-238 was published in the official gazette, Umm Al-Qura, the same day.

• Who: taxpayers whose revenue subject to VAT exceeded SAR 187,500 in 2022, 2023, 2024 or 2025. Crossing the threshold in any single one of those years is enough.
• When: integration with Fatoora is required by 1 February 2027, according to ZATCA's Wave 25 announcement.
• What changed: the threshold is half the previous SAR 375,000 level, and 2025 revenue is counted for the first time. Businesses that were too small or too new for earlier waves are now likely to be caught.

In practice, Wave 25 reaches deep into the small-business segment: clinics, contractors, retailers, restaurants, agencies and service firms that may never have touched an API.

How do you know if Wave 25 applies to you?

ZATCA notifies each targeted taxpayer directly through its approved channels, and it commits to notifying each wave at least six months before the integration date (see the roll-out phases page). Do not wait for a message to start, though. Check your own numbers:

1. Pull the taxable supplies figures from your VAT returns for 2022, 2023, 2024 and 2025.
2. If any year exceeds SAR 187,500, plan on 1 February 2027 as your date.
3. Check the email address and mobile number registered on your ZATCA account and look for the notification there. Make sure the person who receives it knows what it means.
4. If you belong to a VAT group or operate several branches, confirm which legal entity and VAT number the obligation sits with, because onboarding is done per VAT registration.

What does Phase 2 integration require in practice?

Phase 2 adds technical and business requirements on top of Phase 1. Your invoicing solution must produce invoices in ZATCA's XML format with the additional Phase 2 fields, a cryptographic stamp, an invoice hash chain and a QR code, and it must exchange them with Fatoora. Two flows apply:

Area	Clearance	Reporting
Invoice type	Standard tax invoice (mostly B2B and B2G) and its credit and debit notes	Simplified tax invoice (mostly B2C) and its credit and debit notes
Timing	Real time, before the invoice is shared with the buyer	Within 24 hours of issuing the invoice
What ZATCA does	Validates and stamps the invoice, then returns it	Validates and acknowledges the submitted invoice
Customer receives	The cleared invoice only	The invoice immediately at the point of sale
If Fatoora is unreachable	Keep evidence of clearance attempts and clear once connectivity returns	Queue invoices and report within the 24-hour window

ZATCA's detailed e-invoicing guideline also requires that the human-readable invoice is in Arabic (other languages may be added), that invoices are archived and accessible to the Authority, and that you notify ZATCA of any malfunction that stops you issuing e-invoices.

How to connect to the Fatoora platform: the onboarding steps

Every unit that generates and stamps invoices, called an e-invoice generation solution (EGS) unit, must be onboarded separately. A unit can be an ERP instance, a billing server or a POS device, depending on your architecture.

1. Log in to the Fatoora portal with your ZATCA (ERAD) credentials and open the onboarding and management section.
2. Generate one-time passwords (OTPs), one per EGS unit. Each OTP is valid for only one hour, so generate them when your technical team is ready to use them.
3. Create a certificate signing request (CSR) from your solution, containing your VAT number, organisation details, a unique unit serial number and the invoice types the unit will issue (standard, simplified or both).
4. Obtain a compliance CSID (cryptographic stamp identifier) by submitting the CSR with the OTP.
5. Pass the compliance checks by sending sample documents for every invoice type the unit is registered for: invoices, credit notes and debit notes.
6. Request the production CSID, which the unit uses to sign live invoices and authenticate API calls.
7. Go live and monitor clearance responses, reporting acknowledgements, warnings and rejections.

Test in ZATCA's simulation environment before you touch production. If your ERP, POS or accounting software vendor provides a Phase 2 module, much of this is a configuration exercise; if you run custom or legacy systems, you will need middleware or development work. We cover the architecture options (direct integration, middleware, certified providers) and error handling in depth in our technical guide to ZATCA integration for ERP and billing systems.

Wave 25 countdown: a week-by-week action plan to 1 February 2027

Assuming you start in the last week of October 2026, this is a realistic sequence. Compress it only if your vendor already has a tested Phase 2 module.

When	Action	Owner
Weeks 1–2 (late Oct to early Nov 2026)	Confirm scope from 2022–2025 VAT returns, find the ZATCA notification, appoint one accountable owner, list every system that issues invoices or notes	Finance lead
Weeks 2–4 (November)	Ask each software vendor in writing whether its Phase 2 module is live and tested; choose the route for each invoice source: vendor upgrade, middleware or custom integration	Finance and IT
Weeks 4–6 (late Nov to mid Dec)	Clean master data: customer VAT numbers, national address fields, item tax categories, credit-note references; finalise Arabic and bilingual invoice templates	Finance and operations
Weeks 6–9 (mid Dec to early Jan 2027)	Configure or build, then test in the simulation environment with every document type, including edge cases such as zero-rated and exempt lines	IT or integration partner
Weeks 9–11 (January)	Generate OTPs, onboard each EGS unit to production, obtain production CSIDs, run a controlled pilot with real invoices	IT and finance
Weeks 11–13 (late January)	Train sales, accounts and branch staff; write the outage procedure; set up monitoring of rejections and the 24-hour reporting queue	Finance lead
1 February 2027 onwards	Full go-live; review rejections daily for the first month; reconcile Fatoora submissions with your sales ledger and VAT return	Finance

If you issue invoices from point-of-sale terminals, read our guide to ZATCA-compliant POS systems in Saudi Arabia before deciding how many units to onboard.

What are the most common Wave 25 mistakes?

• Ignoring 2025 revenue. A business that was below the threshold in 2022 to 2024 can still be in scope because of 2025.
• Missing an invoice source. Online store orders, a separate billing tool for services, manually issued credit notes or a spreadsheet used by one branch all have to move to a compliant, integrated solution.
• Assuming the software is ready. "ZATCA compliant" on a vendor's website may only mean Phase 1. Ask for evidence of live Phase 2 clearance and reporting.
• Poor customer data. Standard invoices to VAT-registered buyers need correct buyer details, including the buyer's VAT number. Bad master data is the main source of clearance rejections.
• Editing issued invoices. Once issued, an invoice can only be corrected with a credit or debit note. Deleting or amending it is a listed violation.
• Leaving onboarding to the final week. OTPs expire after an hour, compliance checks must pass for every document type and certificates have to be installed correctly on each unit.
• No outage procedure. The guideline expects you to notify ZATCA of malfunctions, keep evidence of clearance attempts and complete clearance or reporting once systems recover. Invoices that are not cleared are not eligible for input VAT deduction by the buyer.

What are the penalties for missing the Phase 2 deadline?

ZATCA's published e-invoicing violations include not issuing or storing e-invoices, issuing simplified invoices without a QR code, omitting the buyer's VAT number on tax invoices, not notifying ZATCA of a system malfunction, and deleting or amending invoices after issuance. Under the graduated approach announced in January 2022, a first violation found on inspection normally results in a warning and three months to correct it. Repeated violations then attract escalating fines reported at SAR 1,000, 5,000, 10,000 and 40,000. Violations not specifically listed fall under the general penalties of the VAT Law, which reach up to SAR 50,000.

The financial risk goes beyond fines. B2B customers who are themselves VAT-registered will increasingly reject invoices that have not been cleared, because they cannot rely on them for input VAT. In practice, non-compliance can delay collections from your best customers.

Which integration route suits a Wave 25 business?

Your situation	Typical route	Watch out for
Cloud accounting or POS with a live Phase 2 module	Activate and onboard through the vendor	Each device or branch may need its own onboarding
ERP with an older version or heavy customisation	Upgrade or add the vendor's e-invoicing add-on	Upgrade timelines and regression testing
Custom or legacy billing system	Middleware that signs, submits and archives invoices	Error handling, retries and monitoring
Several systems issuing invoices	A central invoicing hub integrated with every source	Consistent numbering and hash chains per unit

If you are also reviewing your wider finance platform, our ERP system guide for Saudi Arabia explains which platforms handle Phase 2 natively.

Next step

With the 1 February 2027 deadline about three months away, the businesses that struggle are the ones that start in January. Map your invoice sources this week, get written confirmation from each vendor and book simulation testing for December. Amwaj Solutions designs and builds Fatoora integrations for ERP, billing, POS and e-commerce systems, including custom and legacy platforms. See our ZATCA e-invoicing integration service or contact our team for a readiness review; we respond to consultation requests within 24 to 48 business hours.