If you run finance for a business that operates across borders, or if you work with clients who do, you have probably heard some version of this sentence in the last twelve months: "the government is requiring us to submit invoices electronically now."
What you may not have heard is that every major economy in the world is doing the same thing, at roughly the same time, for exactly the same reason. And the systems they are building are more similar to each other than the different acronyms suggest.
This post explains what is actually happening, country by country, in plain English.
Why this is happening everywhere at once
Tax authorities around the world are dealing with the same problem: the VAT gap.
The VAT gap is the difference between the VAT that businesses theoretically owe and the VAT they actually pay. In the EU, it runs to roughly €61 billion per year. In developing markets it is proportionally larger.
The single most effective way to close the gap is to require businesses to report every invoice to the government in real time, before or immediately after the transaction, rather than in a quarterly return months later. When tax authorities see every invoice as it happens, fraud becomes much harder.
That is the idea driving every mandate covered in this article.
Three architectures, one goal
Before going country by country, it helps to understand that there are really only three ways governments have built these systems.
The clearance model is the strictest. Your invoice does not legally exist until the government validates and signs it. You generate the invoice in your system, submit it to a government portal, the portal validates it and returns a signed copy with a unique identifier and a QR code, and only then can you send it to your buyer. If the portal rejects it, there is no invoice. Italy, Saudi Arabia, and Nigeria all use this model.
The reporting model is looser. You send the invoice directly to your buyer as normal, but you also report a copy to the government within a fixed time window, sometimes hours, sometimes days. If you fail to report, there are penalties, but the invoice itself is still valid. India's system sits in this category, though it is moving toward clearance.
The network model is different again. Rather than a central government portal, invoices travel through a decentralised network of certified access points. Peppol works this way. The government sets the rules and certifies participants, but there is no single hub that everything passes through.
Country by country
Peppol, the European network standard
Peppol is not a mandate. It is a network standard, maintained by OpenPEPPOL, an international non-profit. Think of it as the plumbing that countries build their mandates on top of.
The model is a "four-corner" system: your ERP sends an invoice to your certified Peppol access point, which routes it across the Peppol network to your buyer's access point, which delivers it to their system. No central hub, no government portal in the middle.
Most EU countries have made B2G (business-to-government) invoicing mandatory via Peppol. If you invoice a government department in Germany, France, Italy, or most of Scandinavia, it must go through a Peppol-compliant channel. B2B mandates are coming. France was meant to roll out mandatory B2B e-invoicing in 2024 and delayed to late 2026. Germany, Poland, and others are in various stages of implementation.
The EU's "VAT in the Digital Age" (ViDA) initiative is the overarching framework that will eventually require real-time transaction reporting across all member states, with full effect expected around 2030.
Document format: Peppol BIS (based on UBL XML).
What you actually need to do: Connect to a certified Peppol access point, your ERP vendor or a service provider handles this. You do not submit directly to a government portal; the network handles routing. Your buyer also needs to be reachable on the Peppol network.
India, the IRN system
India launched GST e-invoicing in 2020 and has progressively lowered the threshold at which it applies. Today, any business with annual turnover above ₹5 crore (roughly $600,000) must register every B2B invoice with the Invoice Registration Portal (IRP) before sending it to the buyer.
The flow: you generate the invoice in your system, upload the data in JSON format to the IRP, the IRP validates the GST details and generates an IRN (Invoice Reference Number), a 64-character hash, along with a signed QR code. You then print that IRN and QR code on the invoice you send to your buyer.
The IRN is not actually a sequential number. It is a hash of four fields: your GSTIN, the document type, the document number, and the financial year. This means it is deterministic and can be regenerated, useful for error recovery.
Document format: JSON to the IRP. The physical invoice can be in any format, but must carry the IRN and QR code.
What you actually need to do: Get your GST credentials set up, connect your ERP to a certified IRP, and ensure every B2B invoice generated above the threshold goes through the registration flow before despatch.
Italy, SDI, the original clearance mandate
Italy was the first country to mandate B2B e-invoicing across the economy, doing so in January 2019. Every invoice issued in Italy, B2B, B2G, and increasingly B2C, must pass through the SDI (Sistema di Interscambio, the "interchange system") operated by the Italian Revenue Agency.
The flow: you prepare the invoice in FatturaPA format (an Italian XML standard), transmit it to the SDI, the SDI validates the format and the buyer's tax code, routes a copy to the buyer's registered mailbox, and returns a receipt to you. If it rejects the invoice, wrong format, invalid VAT number, duplicate document number, there is no invoice. You fix it and resubmit.
The SDI stores a copy of every invoice permanently. Italy's VAT gap has fallen significantly since 2019. The clearance model works.
Document format: FatturaPA XML (Italian standard, not standard UBL).
What you actually need to do: Either integrate your ERP directly with the SDI via their API, or use one of the many intermediaries that handle the transmission for you. Every invoice issued to an Italian entity must go through this channel.
Saudi Arabia, ZATCA and Fatoora
Saudi Arabia's mandate is administered by ZATCA (Zakat, Tax and Customs Authority) and runs in two phases.
Phase 1, which started in December 2021, required businesses to generate and store invoices electronically in a structured format, but did not require integration with ZATCA's systems. Phase 2, rolling out since January 2023 in waves based on taxpayer size, requires real-time integration with ZATCA's Fatoora portal.
There are two invoice types: Standard invoices (B2B) go through clearance, submitted to Fatoora, validated, stamped with a Cryptographic Stamp Identifier (CSID), then sent to the buyer. Simplified invoices (B2C) use a reporting model, you report them to ZATCA within 24 hours.
What makes ZATCA technically interesting is hash chaining: each invoice must include a hash of the previous invoice in the sequence. This creates a tamper-evident chain, you cannot quietly delete or modify a past invoice without invalidating everything that comes after it.
Document format: UBL 2.1 XML.
What you actually need to do: Phase 2 requires API integration with Fatoora. Check which wave applies to your taxpayer segment, get your ZATCA credentials, and ensure your ERP handles the hash-chaining logic correctly.
Nigeria, NRS MBS
Nigeria's mandate is administered by the Nigeria Revenue Service (NRS) through the Mandatory Billing System (NRS MBS). The architecture is a clearance model, the same fundamental approach as Italy and Saudi Arabia.
The flow: you generate an Invoice Reference Number (IRN) in your system using the formula {InvoiceNumber}-{ServiceID}-{YYYYMMDD}, submit the invoice payload to the NRS API for validation, and then submit again for signing. The NRS signs the invoice and returns a Cryptographic Stamp Identifier (CSID) and QR data. The IRN and QR code appear on every printed invoice.
There is also a separate ATRS (Automated Tax Remittance System) for B2C POS receipts, which uses an OAuth-based flow and generates a payment code for each transaction.
The NRS system uses JSON throughout, following UBL BIS Billing 3.0 field names, the same international standard that underlies Peppol. Nigeria built its system on an internationally recognised technical foundation.
Document format: JSON (UBL BIS Billing 3.0 field names).
What you actually need to do: Register on the NRS e-Invoice portal, get your Business ID, Service ID, API key, and API secret. Connect your ERP. Every B2B Sales Invoice needs to go through validate → sign before being sent to your buyer.
What all five share
Despite the different names and portal URLs, the underlying requirements are consistent.
Structured data, not PDFs. Every system requires invoice data in a machine-readable format, XML or JSON. A PDF scanned from paper does not qualify anywhere.
A government-issued identifier on every invoice. IRN in India and Nigeria. SDI protocol number in Italy. CSID in Saudi Arabia. Peppol document ID in the EU network. The identifier is proof that the invoice was registered.
A QR code for verification. Every system either mandates or strongly encourages a QR code that allows the buyer, or an auditor, to verify the invoice's authenticity against the government's records.
Mandatory field completeness. Tax identification numbers for both seller and buyer. Itemised line amounts. Tax category codes. HSN or service codes. Every system rejects invoices with missing or invalid required fields.
Penalties for non-compliance. Italy issues administrative sanctions per invoice. Saudi Arabia penalises up to 50,000 SAR. India assesses penalties under GST law. Nigeria's NRS has enforcement powers under the Nigeria Tax Act 2025.
Where they genuinely differ
Clearance vs reporting. In a clearance model, Italy, Saudi B2B, Nigeria, your invoice does not legally exist until the government approves it. In a reporting model, India, Saudi B2C, the invoice is valid but you owe the government a report. The clearance model leaves no room for late reporting.
Centralised hub vs decentralised network. Peppol has no single government hub. Every other system in this article routes everything through a central government portal. These are fundamentally different architectures with different failure modes.
Document format. UBL XML (Peppol, Saudi), FatturaPA XML (Italy), JSON UBL (Nigeria), JSON to IRP (India). They are all structured data, but they are not interchangeable.
B2B vs B2G scope. Peppol mandates are currently B2G in most countries. India, Italy, Saudi Arabia, and Nigeria mandate B2B. The EU's ViDA initiative will close this gap across Europe eventually.
Speed of clearance. The NRS and SDI respond within seconds in normal operation. ZATCA's Fatoora can take longer under high load. Slow clearance creates operational problems for high-volume businesses, which is why most systems provide a simplified B2C path with a longer reporting window.
What you actually need to do
If you operate in only one of these markets, the answer is: get your ERP integrated with that market's portal or network before the mandate applies to your revenue tier.
If you operate across multiple markets, the more important question is whether your ERP vendor has built country-specific compliance modules for each jurisdiction, rather than expecting you to manage the different formats and API integrations yourself.
Five questions worth asking your ERP or finance software vendor:
- Does this system generate the mandate-compliant identifier (IRN, SDI number, CSID) natively, or do I need a third-party add-on?
- Is submission to the government portal automatic on invoice posting, or is it a manual step?
- What happens when the government portal rejects an invoice, is there a retry mechanism?
- Can I see the submission status of every invoice in one place?
- What is the audit trail if NRS, ZATCA, or SDI requests invoice records?
The broader picture
The direction of travel is clear. Within five years, every significant economy will have some form of real-time invoice reporting to a tax authority. The format and architecture will vary. The outcome, governments seeing every transaction as it happens, will not.
For businesses, this is not as frightening as it sounds. The countries that have already gone through full mandates, Italy most visibly, report that once the initial integration is done, day-to-day operations are largely unchanged. The ERP submits, the government responds, the invoice goes out. It adds seconds, not hours.
What it does require is software that was actually built for it.
Zinye ERP includes built-in Nigeria NRS MBS compliance, PAYE under the NTA 2025, pension, NHF, NHIS, NSITF, ITF, WHT, and NDPR, for businesses and finance teams operating in Nigeria. If you work with Nigerian businesses and want to explore what that looks like in practice, you can register your interest at zinyecrm.zinye.com/partner/new.