KSA E-Invoicing Phase 2 Wave 24: Deadline & Readiness Guide
ZATCA confirmed a 30 June 2026 deadline for Wave 24 integration. Here is the accountant-focused checklist, ERP failure points, and month-end controls you need to act on now.
By the SuperAccountant Editorial Team
Wave 24 Is Not a Drill — Your Integration Clock Is Running
If your client's taxable revenues sit above SAR 375,000 for the relevant base period and they are not yet connected to the FATOORA platform, they are already in the implementation window. ZATCA confirmed Wave 24 integration requirements with a hard compliance deadline of 30 June 2026 (corresponding to 5 Muharram 1448H). That is not the date you start planning — that is the date your system must be live, tested, and pushing e-invoices in real time. Most articles will tell you what Wave 24 is. This one tells you what to do about it before month-end controls break and ZATCA penalties land.
What Wave 24 Actually Requires (The Short Brief)
Phase 2 of ZATCA's e-invoicing mandate — known as the Integration Phase — requires taxpayers to connect their ERP or billing systems to the FATOORA platform via a Continuous Transaction Control (CTC) model. Under ZATCA's Implementing Regulation Articles 53–60 (accessible at zatca.gov.sa), the obligations break down as follows:
- Standard tax invoices (B2B): Must be cleared by FATOORA before being issued to the buyer. ZATCA returns a cryptographic stamp and UUID; without these, the document is not a valid tax invoice.
- Simplified tax invoices (B2C): Must be reported to FATOORA within 24 hours of issuance per Article 60 of the Implementing Regulation.
- Credit and debit notes: Subject to the same clearance/reporting cycle as their source invoice type.
Wave 24 means ZATCA formally notified a cohort of taxpayers — businesses whose annual revenues crossed the SAR 375,000 threshold in the designated base period — that they fall inside this wave. Once notified, the six-month onboarding window opens and the 30 June 2026 deadline is the outer boundary.
The FATOORA Integration Checklist (Audit-Ready Version)
Run through this before you declare the client ready. Each item maps to a ZATCA technical requirement.
| # | Checklist Item | Owner | Status |
|---|---|---|---|
| 1 | ZATCA notification letter received and acknowledged | CFO / Tax Manager | ☐ |
| 2 | ERP/billing system identified as Mu'tamad-compatible or vendor confirmed compliant | IT / Finance | ☐ |
| 3 | Cryptographic Stamp Device (CSID) generated via FATOORA portal | IT | ☐ |
| 4 | UBL 2.1 XML schema version confirmed (ZATCA-SA-UBL-2.1) | IT / ERP vendor | ☐ |
| 5 | QR code field (Tag 1–6 minimum for simplified; full clearance XML for standard) implemented | ERP vendor | ☐ |
| 6 | Sandbox testing completed — at least 50 cleared and 50 reported invoices | IT / Finance | ☐ |
| 7 | Production onboarding (PCSID) completed with FATOORA | IT | ☐ |
| 8 | Rejection-handling workflow documented and tested | Finance | ☐ |
| 9 | Archive policy confirmed — 7-year retention per ZATCA Implementing Regulation Article 66 | Finance / Legal | ☐ |
| 10 | Month-end VAT reconciliation updated to pull UUID-confirmed invoices only | Accountant | ☐ |
Do not skip item 8. Rejection-handling is where most live implementations break down.
Common ERP Failure Points (And How to Catch Them Early)
Three patterns account for the majority of Wave 24 integration failures seen in practice:
1. Incorrect invoice type code mapping
ZATCA requires a specific three-digit invoice type code in the XML (0100000 for standard, 0200000 for simplified, and so on for credit/debit notes). ERPs localised for global markets often default to a generic UBL type code that FATOORA rejects outright. Run a schema validation against the ZATCA-published XSD before sandbox testing begins, not after.
2. Seller TIN and VAT registration number mismatch FATOORA validates the seller's Tax Identification Number (TIN) and VAT number against ZATCA's register in real time. If the ERP's company master holds an old TIN (common after mergers or branch restructures) the clearance API returns a 400-level error and the invoice never reaches the buyer. Cross-check the ERP company master against the ZATCA taxpayer portal before you submit a single test invoice.
3. Timestamp and timezone errors
ZATCA requires invoice timestamps in Arabian Standard Time (UTC+3) formatted as YYYY-MM-DDTHH:MM:SS. Systems configured for UTC — common on cloud ERPs hosted in European data centres — will stamp invoices one, two, or three hours behind. FATOORA accepts the invoice but the sequence number and timestamp conflict creates a VAT period attribution problem that surfaces at month-end. Set the ERP application layer explicitly to AST, not just the server OS.
Month-End Controls You Must Update Before Go-Live
This is the section most readiness guides skip entirely. Connecting to FATOORA changes your month-end close process in three concrete ways:
VAT return input data Your VAT return (Form VAT-01) for output tax must now be reconciled against ZATCA-cleared invoices, not your internal AR ledger. The two should match — if they do not, you have either uncleared invoices counted as revenue, or rejected invoices sitting in the AR sub-ledger. Build a three-way reconciliation: (a) AR ledger output VAT, (b) FATOORA clearance log UUID count × average VAT amount, (c) VAT-01 Box 1 figure. Any variance above SAR 500 warrants investigation before submission.
Sequence number continuity ZATCA requires invoices to carry an unbroken sequential counter (ICV — Invoice Counter Value). A month-end system restart, ERP upgrade, or failover to a backup server can reset this counter. A reset triggers a ZATCA audit flag. Assign ownership of the ICV counter to a named IT contact, back it up daily, and include counter continuity in your month-end IT checklist.
Credit note matching Under Phase 2, every credit note must reference the UUID of the original cleared invoice. If a sales credit is raised in the new month for an invoice issued before go-live (i.e., a pre-Phase-2 invoice), there is no UUID to reference. ZATCA's technical guidelines allow a workaround for this transition period — use a dummy reference compliant with Article 54(4) of the Implementing Regulation and document the reason in your audit file. Do not leave this undefined in your procedures manual.
Penalties for Non-Compliance and How ZATCA Enforces Them
ZATCA's penalty framework for Phase 2 non-compliance operates under the E-Invoicing Regulations issued under the VAT Law (Royal Decree M/113 dated 11/11/1438H). Issuing a tax invoice without Phase 2 clearance is treated as issuing an invalid invoice. Per the VAT Implementing Regulation Article 67, penalties scale with the number of non-compliant invoices and can reach up to SAR 50,000 per assessment cycle. ZATCA has indicated it will conduct targeted field reviews on Wave cohorts after their deadline passes, focusing on VAT return reconciliation mismatches that signal bypassed clearance.
The practical risk for accountants: if you sign off on a VAT return where output VAT is derived from non-cleared invoices, you are attesting to figures ZATCA cannot independently verify. That exposure sits with the signatory, not just the system.
What To Do in the Next 30 Days
If the 30 June 2026 deadline is six months away and you have not started, here is your sequenced action plan:
- Weeks 1–2: Confirm ERP vendor readiness. Get written confirmation of ZATCA Phase 2 compliance and the UBL schema version supported. If the vendor cannot confirm, escalate to management immediately — switching billing systems in Q1 2026 is possible but painful.
- Weeks 3–4: Generate CSID in the FATOORA sandbox environment. This requires a ZATCA portal login with the authorised representative's NIC. Do not delegate this to the vendor without a formal power of attorney.
- Month 2–3: Run structured sandbox testing. Document every rejection, root-cause it, and retest. ZATCA's sandbox environment is available at the developer portal linked from zatca.gov.sa.
- Month 4: Complete production onboarding (PCSID). Issue first live cleared invoice. Run the three-way VAT reconciliation for the first live week.
- Month 5–6: Operate in production, stress-test rejection-handling, and update the month-end close checklist. Have your external auditor review one month's FATOORA clearance log before the first post-go-live VAT return is filed.
Want to benchmark your current readiness against peers? Try the SuperAccountant readiness quiz — it takes under five minutes and flags your highest-priority gaps.
The Accountant's Role Is Now System Owner, Not Just Reporter
Wave 24 is a systems compliance obligation, but the accountability lands on finance, not IT. When ZATCA audits, they pull the VAT return, the FATOORA clearance log, and the AR ledger simultaneously. The reconciling accountant who built robust controls will be able to walk an auditor through every SAR of output VAT in under an hour. The one who outsourced readiness entirely to the ERP vendor will not.
Build the controls. Own the month-end reconciliation. Document the rejection-handling policy. ZATCA Phase 2 was designed to make VAT self-auditing through the transaction data itself — your job is to make sure your client's data tells the right story.
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