Greece is one of the few European countries where e-invoicing is not arriving as a new system but as the next layer of an already mature one. Since 2021, Greek businesses have operated under myDATA, a near-real-time e-reporting and digital bookkeeping regime run by the Independent Authority for Public Revenue (AADE), where every transaction is uploaded, validated, and stamped with a unique identifier (the MARK) and a QR code. In 2026, Greece is upgrading that reporting layer into a mandatory structured e-invoicing regime for domestic B2B transactions, phased by company size. The first wave went live on 2 March 2026 (postponed from the originally announced 2 February). This is not a clean cutover but a staged ramp-up built on the existing myDATA infrastructure.
This article walks through what businesses operating in Greece face today, what the 2026 B2B mandate introduces, how the dates and penalties actually work after the February 2026 postponement, and how to prepare. Greece is a useful case study in how a country with a strong existing reporting backbone converts to full e-invoicing with relatively little disruption compared with a from-scratch build.
Before getting into the technical detail, it helps to separate the layers a business in Greece operates under. Each has its own legal basis, scope, and timeline:
- Layer 1:myDATA e-reporting and e-books. In force since 2021. All Greek-established taxpayers transmit income and expense transaction data to the AADE myDATA platform in near real time. Each document receives a MARK (unique registration number) and a QR code. This is the reporting backbone everything else builds on.
- Layer 2:B2G e-invoicing (Peppol). Mandatory for public-procurement suppliers, phased in from 2023–2025. B2G invoices follow EN 16931 and the Greek Peppol CIUS, are validated through myDATA (receiving a MARK), and are delivered to public bodies through accredited Peppol Access Points.
- Layer 3:Domestic B2B e-invoicing mandate (2026). The new obligation. Structured electronic invoices for domestic B2B transactions, transmitted through accredited providers or AADE’s free tools, validated by myDATA. Phase 1 (large businesses) live from 2 March 2026; Phase 2 (all remaining businesses) from 1 October 2026.
- Layer 4:e-transport / digital delivery notes. A parallel goods-movement control regime. Phase A (digital issuance of transport documents) mandatory since 1 December 2025; Phase B (full digital tracking of loading, receipt, and quantity checks) mandatory from 1 May 2026.
- Layer 5:ViDA cross-border (firm under EU law). From 1 July 2030, structured e-invoicing and digital reporting become mandatory for intra-Community B2B supplies under Council Directive (EU) 2025/516. Greece, with a pre-existing domestic DRR model, must also align that model with the EU framework by 2035.
Each layer applies independently. The 2026 B2B mandate (Layer 3) is the focus of this article, but it is best understood as a structural upgrade to Layer 1, not a standalone new system.
What is E-Invoicing in Greece?
E-invoicing in Greece means the creation, transmission, validation, and reporting of structured invoice data through the AADE myDATA platform. A compliant Greek e-invoice is not a PDF emailed to a customer, it is structured data that must be transmitted to myDATA and validated before it is recognised for tax purposes. On successful registration, myDATA assigns a MARK (Mштрo Aντιστoίχισης / unique registration number) and the invoice carries a QR code that links back to its myDATA record. This produces a continuous transaction control (CTC) environment that sits much closer to clearance than to simple post-issuance reporting.
The supervising authority is the Independent Authority for Public Revenue (AADE), operating under the Ministry of National Economy and Finance. AADE runs myDATA, accredits e-invoicing service providers (known in Greek as Y.PA.H.E.S.), and provides free issuance tools. Greece’s digital tax stack also overlaps with a SAF-T-style structured data philosophy: myDATA’s e-books function as a continuously updated structured ledger rather than a periodic file, which is one reason Greece did not need to build a separate SAF-T extraction regime.
What is B2B e-invoicing in Greece?
Domestic B2B e-invoicing became mandatory in 2026, phased by company size. Under the mandate, the supplier issues a structured electronic invoice and transmits it to myDATA through an accredited provider or an AADE free tool. AADE validates the invoice, myDATA generates the MARK, and the transaction is registered. For domestic transactions, the receiving business is obliged to accept the e-invoice, acceptance is not optional on the buyer side.
Scope is more precise than “domestic B2B” suggests. The mandate covers domestic B2B transactions and sales to businesses in non-EU (third) countries. For intra-EU B2B transactions, e-invoicing remains optional, if the EU counterparty refuses the electronic invoice, an alternative delivery method may be used. This distinction matters for Greek exporters: a shipment to a German customer is optional, a shipment to a UK or US customer is in scope.
What is B2G e-invoicing in Greece?
B2G e-invoicing has been mandatory for public-procurement suppliers since the 2023–2025 phased rollout. B2G invoices must comply with the European standard EN 16931 and the Greek Peppol CIUS. The flow combines the two Greek control mechanisms: the invoice is first validated by myDATA and assigned a MARK, then transmitted through accredited Peppol Access Points to the relevant public authority. This ensures that only validated, tax-compliant invoices circulate within the public-procurement ecosystem. Greece adopted Directive 2014/55/EU, which requires public bodies to be capable of receiving and processing structured e-invoices.
What is B2C e-invoicing in Greece?
There is no mandatory B2C e-invoicing framework in Greece. Consumer transactions are reported through existing fiscal and digital bookkeeping obligations, retail receipts flow into myDATA through fiscal electronic devices and approved channels, but structured e-invoicing as such is not mandated for B2C. The 2026 mandate is focused on domestic B2B and non-EU exports.
This should be described carefully. The fact that B2C is outside the e-invoicing mandate does not mean B2C is outside myDATA. Retail and consumer transaction data still reaches AADE through the e-reporting layer. What is not required is the structured-invoice issuance-and-validation cycle that applies to B2B.
E-Invoicing in Greece 2026 Last Updates
The defining 2026 development is the postponement of Phase 1. The Greek Ministry of National Economy and Finance and AADE had announced (on 16 September 2025) that mandatory B2B e-invoicing for large businesses would begin on 2 February 2026. On 17 February 2026, via joint press release and Decision A.1044/2026, the authorities postponed the Phase 1 start date to 2 March 2026, with the gradual implementation window moved from 2 February–31 March to 2 March–3 May 2026.
The corrected and current timeline is:
- Phase 1 (large businesses, FY2023 gross revenue over EUR 1 million): mandatory from 2 March 2026. Gradual implementation window 2 March – 3 May 2026, during which businesses may run existing ERP/accounting systems in parallel or use AADE’s entry form. Penalties apply from 3 May 2026. Approximately 38,000 businesses are in this first wave.
- Phase 2 (all remaining businesses established in Greece): mandatory from 1 October 2026, with a transition period until 31 December 2026.
The legal foundation is Council Implementing Decision (EU) 2025/502, published by the Council of the EU on 25 February 2025, authorising Greece to derogate from Articles 218 and 232 of Directive 2006/112/EC and mandate B2B e-invoicing. The derogation runs from 1 July 2025 until 31 December 2027, though once ViDA enters force the EU-level permission requirement falls away.
Two further 2026 developments matter. First, early-adoption incentives: businesses that adopt e-invoicing early receive tax benefits including a super-deduction and increased depreciation on related implementation costs, plus a faster VAT-refund track. Second, businesses must file a declaration with AADE specifying their chosen e-invoicing transmission method (accredited provider, Timologio, or myDATAapp) before they can benefit from the grace period.
| Why this matters in 2026Greece’s pattern is repeated stepwise deferral, not cancellation. The Phase 1 date has already moved once (February to March 2026), and the e-transport Phase B and the older myDATA waves have all slipped before. The mistake businesses make is reading each deferral as “Greece is slowing down” and pausing their projects. The correct reading is the opposite: the direction is fixed and the infrastructure already exists. myDATA has been live since 2021, accredited providers are operational, and 38,000 large businesses are already in the Phase 1 wave. A business that uses each deferral as breathing room to complete testing, rather than as a reason to stop, arrives at its mandatory date ready. A business that treats deferrals as permission to wait arrives unprepared, because the next deferral is never guaranteed. |
E-Invoicing in Greece Deadlines and Compliance Roadmap
The table below reflects the corrected post-17-February-2026 timeline. The B2G and myDATA milestones are already in force; the 2026 B2B dates are firm in law (Decision A.1044/2026) following the postponement; the ViDA date is fixed by EU directive.
| Date | Milestone | Status |
|---|---|---|
| 2019 | Greece adopts Directive 2014/55/EU (public bodies must receive structured e-invoices) | Done |
| 2021 | myDATA e-reporting and e-books go live; MARK and QR introduced | In effect |
| 2023–2025 | B2G e-invoicing phased in (EN 16931 + Greek Peppol CIUS) | In effect |
| 25 February 2025 | Council Implementing Decision (EU) 2025/502 authorises B2B mandate | Done |
| 1 December 2025 | e-transport / digital delivery note Phase A mandatory | In effect |
| 16 September 2025 | AADE announces original Phase 1 date of 2 February 2026 | Superseded |
| 17 February 2026 | Decision A.1044/2026 postpones Phase 1 to 2 March 2026 | Done |
| 2 March 2026 | Phase 1 B2B mandatory: large businesses (FY2023 revenue over EUR 1M) | In effect |
| 2 March – 3 May 2026 | Phase 1 gradual implementation window (parallel systems allowed) | In effect |
| 1 May 2026 | e-transport / digital delivery note Phase B mandatory | Planned |
| 3 May 2026 | Phase 1 penalties begin | Planned |
| 1 October 2026 | Phase 2 B2B mandatory: all remaining established businesses | Planned |
| 31 December 2026 | Phase 2 transition period ends | Planned |
| 1 July 2030 | ViDA cross-border B2B e-invoicing and digital reporting deadline | Firm (EU) |
Greece’s e-waybill regime (the digital delivery note) runs in parallel with the invoicing mandate and is a distinct obligation. For broader regional context, see E-Invoicing in Europe, and for the EU framework that will eventually absorb the Greek domestic model, see VAT in the Digital Age (ViDA).
Is e-Invoicing Mandatory in Greece?
The honest answer is: yes, and the rollout is already under way. As of May 2026:
- B2G: Mandatory for public-procurement suppliers (EN 16931 + Greek Peppol CIUS, via myDATA validation).
- B2B (Phase 1): Mandatory since 2 March 2026 for large businesses (FY2023 revenue over EUR 1 million); penalties from 3 May 2026.
- B2B (Phase 2): Mandatory from 1 October 2026 for all remaining established businesses.
- B2C: No e-invoicing mandate; consumer data still flows to myDATA through the reporting layer.
- Intra-EU B2B: Optional. Non-EU exports are in scope; intra-EU is not.
- Non-established businesses: Businesses only VAT-registered in Greece without a physical establishment are generally outside the mandate, per Council Decision (EU) 2025/502.
This should be described carefully. Unlike South Africa or the Netherlands, where the mandate is still being designed, Greece’s B2B mandate is enacted and live. The only moving parts now are the phase-by-phase dates, which have a history of incremental postponement. A business in scope for Phase 1 is legally obliged today; a business in scope for Phase 2 should treat 1 October 2026 as firm while staying alert to possible deferral.
Greece E-Invoicing Requirements
Core requirements
The operational requirements for compliant Greek e-invoicing are:
- Structured invoice data. Invoices must be generated in a structured electronic format that myDATA can process and validate. PDFs alone do not satisfy the e-invoicing requirement.
- Transmission through accredited providers (or AADE free tools). B2B e-invoices must be submitted through an AADE-accredited e-invoicing service provider (Y.PA.H.E.S.) or through AADE’s free tools, the Timologio web application or the myDATAapp mobile application.
- myDATA validation and MARK. Invoice data must reach myDATA, where it is validated and assigned a unique MARK identifier before the invoice is recognised for tax purposes.
- QR code. Electronic invoices must carry a QR code linking the document to its myDATA verification record.
- Digital bookkeeping integration. Invoice data must synchronise with the taxpayer’s myDATA e-books, so that issued invoices and the digital ledger remain consistent.
- Buyer acceptance. For domestic B2B transactions, the receiving business is obliged to accept the structured e-invoice.
- Archiving. Electronic invoice records must generally be retained for five years from the year of issuance, extendable to up to ten years in specific cases (each case assessed individually).
Current rules vs. expected end-state: a side-by-side view
The table below summarises how the Greek requirements evolve as the B2B mandate completes its phased rollout.
| Compliance area | Before 2026 mandate | Under the 2026 B2B mandate |
|---|---|---|
| Reporting | myDATA e-reporting after issuance | Structured e-invoice validated by myDATA at issuance |
| Format | Any format; data reported to myDATA | Structured XML (myDATA / Greek CIUS); PDF alone not valid |
| Transmission | Direct or via provider to myDATA | Accredited provider (Y.PA.H.E.S.) or AADE free tools |
| Validation | MARK on reported data | MARK required before invoice is tax-valid |
| Buyer side | No acceptance obligation | Domestic buyer must accept the e-invoice |
| Scope | Reporting applies broadly | Domestic B2B + non-EU export mandatory; intra-EU optional |
| B2G | EN 16931 + Peppol CIUS | EN 16931 + Peppol CIUS (continuity) |
| Archiving | 5 years | 5 years (up to 10 in specific cases) |
When Will E-invoices in Greece Become Mandatory?
For Phase 1 (large businesses), e-invoicing is already mandatory: the obligation began on 2 March 2026 for businesses with FY2023 gross revenue exceeding EUR 1 million. A gradual implementation window runs from 2 March to 3 May 2026, during which businesses may operate parallel systems; penalties begin on 3 May 2026. This is the date corrected by Decision A.1044/2026, the originally announced 2 February 2026 date is superseded.
For Phase 2 (all remaining established businesses), e-invoicing becomes mandatory from 1 October 2026, with a transition period until 31 December 2026.
For cross-border intra-Community B2B, the EU ViDA framework applies from 1 July 2030 under Council Directive (EU) 2025/516. Greece’s existing domestic DRR model must additionally align with the EU framework by 2035.
This should be described carefully. The Greek timeline has a well-documented history of incremental deferral, the Phase 1 date itself moved from February to March 2026, and the e-transport and older myDATA waves have slipped repeatedly. Businesses should plan around the legal dates while remaining alert to the possibility of further postponement, and should never treat a deferral as a reason to pause an implementation project.
Who is Obliged to Use e-Invoicing in Greece?
In scope
- Large businesses (Phase 1): established in Greece with FY2023 gross revenue exceeding EUR 1 million, mandatory since 2 March 2026.
- All other established businesses (Phase 2): mandatory from 1 October 2026.
- Public-procurement suppliers: already in scope under the B2G regime.
- Greek businesses exporting to non-EU countries: in scope for those transactions.
Out of scope or optional
- Non-established businesses: those only VAT-registered in Greece without a physical establishment are generally exempt, per Council Decision (EU) 2025/502.
- Intra-EU B2B transactions: e-invoicing remains optional; if the EU counterparty refuses, an alternative method may be used.
- B2C transactions: outside the e-invoicing mandate (though still within myDATA reporting).
How to Generate e-Invoices in Greece?
The transmission methods
A business in scope must choose and declare one of the following transmission methods to AADE:
- Accredited e-invoicing service provider (Y.PA.H.E.S.). A provider accredited by AADE handles structured-invoice generation, myDATA transmission, MARK retrieval, QR code generation, and delivery. This is the standard route for businesses with meaningful volume or ERP integration needs.
- AADE Timologio application. A free web-based issuance tool provided by AADE, suitable for smaller taxpayers without complex ERP integration.
- AADE myDATAapp. A free mobile application for issuing and transmitting invoices, aimed at micro and small businesses.
The technical workflow
- The supplier generates the invoice in its ERP, billing, or accounting system in the structured myDATA / Greek CIUS format.
- The invoice data is submitted through the chosen accredited provider or AADE free tool.
- The data is transmitted to myDATA, where AADE validates it.
- myDATA returns the unique MARK identifier; the QR code is generated and applied.
- The structured e-invoice is delivered to the customer (who, if a domestic business, must accept it).
- The transaction is reflected in the taxpayer’s myDATA e-books, and the record is archived for the statutory period.
For B2G transactions, the validated invoice is additionally routed through the Peppol network to the relevant public authority via an accredited Access Point. RTC operates as an e-invoicing service provider supporting myDATA transmission and Peppol exchange, and can act in the accredited-provider role for both the B2B mandate and B2G procurement flows.
Greece e-Invoicing Implementation Checklist
A practical preparation checklist for businesses operating in or with Greece, sequenced by priority:
- Determine your phase. Confirm whether the entity falls into Phase 1 (FY2023 revenue over EUR 1 million, mandatory since 2 March 2026) or Phase 2 (all remaining businesses, mandatory from 1 October 2026).
- File the AADE declaration. Submit the declaration to AADE specifying the chosen e-invoicing transmission method (accredited provider, Timologio, or myDATAapp). Without this declaration, the grace period does not apply and invoices may not be treated as legally issued.
- Review B2B and B2G transaction flows. Map domestic B2B, non-EU export, intra-EU, and public-procurement flows separately, since each has a different obligation level.
- Assess ERP and accounting system readiness. Verify that the ERP or accounting system can output structured myDATA / Greek CIUS format and integrate with an accredited provider or AADE tool.
- Select an accredited provider. Choose an AADE-accredited e-invoicing service provider (Y.PA.H.E.S.) or confirm use of a free AADE tool. Accreditation status is the determinative factor, not general e-invoicing capability.
- Verify myDATA integration and MARK handling. Confirm that the solution retrieves the MARK and reconciles it back to the source invoice and the e-books.
- Prepare QR code generation. Ensure the issuing solution generates the myDATA-linked QR code on every invoice.
- Review master data and tax mappings. Clean up counterparty VAT numbers, classification codes, and VAT category mappings, since errors surface immediately at validation.
- Test transmission and validation. Run end-to-end tests through the gradual implementation window before penalties apply (3 May 2026 for Phase 1).
- Design exception and correction handling. Define procedures for rejected invoices, cancellations, and credit notes within the myDATA framework.
- Address e-transport obligations. If the business moves goods, prepare separately for the digital delivery note regime, Phase A already mandatory, Phase B mandatory from 1 May 2026.
- Consider early-adoption incentives. Evaluate the super-deduction and increased-depreciation incentives available for early adoption of e-invoicing.
FAQs About E-Invoicing in Greece
What is the standard format for e-Invoices in Greece?
For B2B transactions, Greece uses structured XML based on the myDATA specifications and Greek CIUS requirements. For B2G transactions, invoices must comply with Peppol BIS Billing 3.0 and the Greek Peppol CIUS. Structured electronic data is mandatory in both cases; a PDF on its own does not satisfy the e-invoicing requirement.
How does e-invoicing benefit businesses in Greece?
E-invoicing automates invoice processing, reduces manual data entry, improves tax-reporting accuracy, and strengthens audit readiness. Because it is built on myDATA, it also simplifies digital bookkeeping obligations, the same data feeds both the invoice and the e-books, and improves transparency between taxpayers and AADE. Early adopters additionally benefit from a super-deduction, increased depreciation on implementation costs, and a faster VAT-refund track.
Can small businesses benefit from e-invoicing in Greece?
Yes. Small businesses benefit from reduced administrative effort, better invoice tracking, and faster compliance. Greece provides free tools, the Timologio web application and the myDATAapp mobile application, so that smaller taxpayers can comply without investing in complex ERP integration. Phase 2 brings these businesses into scope from 1 October 2026, giving them time to adopt the free tools or a low-volume accredited provider.
Are there any exemptions to the e-invoicing requirements in Greece?
Yes. Businesses only VAT-registered in Greece without a physical establishment are generally exempt from the domestic B2B mandate, per Council Decision (EU) 2025/502. Intra-EU B2B transactions are optional rather than mandatory. B2C transactions are outside the e-invoicing mandate (though still within myDATA reporting). The e-transport regime also carries specific sector exemptions (for example, certain network-maintenance spare parts, industrial minerals, and free school-textbook distribution).
How can businesses in Greece prepare for the e-invoicing transition?
Determine the applicable phase, file the AADE transmission-method declaration, review ERP and myDATA integration readiness, select an accredited provider or AADE free tool, clean up master data and tax mappings, and test invoice transmission and validation end-to-end before penalties apply. Businesses that move goods should prepare separately for the digital delivery note (e-transport) regime. Use the gradual implementation windows for testing rather than as a reason to delay.
What software solutions are available for e-invoicing in Greece?
Three categories: AADE-accredited e-invoicing service providers (Y.PA.H.E.S.); ERP-integrated myDATA solutions; and AADE free tools (Timologio and myDATAapp). The chosen solution should support structured invoice generation, myDATA reporting, MARK retrieval, QR code generation, e-books synchronisation, and long-term archiving. RTC operates as an e-invoicing service provider supporting myDATA transmission and Peppol exchange for both B2B and B2G flows.
Are there penalties for non-compliance with e-invoicing regulations in Greece?
Yes, and the penalty position changed with the 2026 mandate. Under the joint press release of 17 February 2026, failure to issue an electronic invoice is treated as non-issuance of an invoice, triggering penalties under the Code of Tax Procedure: for VATable transactions, a fine equal to 50% of the VAT due on the unissued invoice; for non-VATable transactions, EUR 500 to EUR 1,000 per tax audit depending on the accounting system. For Phase 1, these penalties apply from 3 May 2026 (after the gradual implementation window). Separately, the older myDATA transmission-failure penalty regime under Law 5073/2023 remains relevant for reporting breaches, a fine of up to a percentage of the net value of non-transmitted documents, subject to caps. The e-invoicing-specific penalty (50% of VAT) is the one that matters most under the new mandate.