W System / Blog / Greece e-invoicing 2 November 2026 for software

Greece e-invoicing from 2 November 2026: what software builders need to ship

By Zifeng Wei, W System · Published 19 October 2026 · All articles

In short: from 2 November 2026 the remaining Greek businesses (2023 gross revenue up to EUR 1 million) must issue electronic invoices for domestic B2B wholesale, non-EU B2B wholesale and B2G, under joint decision A.1128/2025 as amended by A.1197/2026. Large businesses (over EUR 1 million) have already been in since 2 March 2026. Until 31 January 2027 a declared ERP or special-form path can still run in parallel; from 1 February 2027 only an AADE-licensed provider or AADE's timologio / myDATAapp may issue. This page is for invoicing and ERP builders: timeline, what is in scope, the provider vs ERP split, MARK / QR / EN 16931 download, a checklist, and a live EN 16931 example.

Timeline (second period)

Date	What happens	Source
2 Mar 2026	First period: issuers with 2023 gross revenue > EUR 1 million must issue e-invoices for art. 1 transactions; recipients must accept domestic B2B and B2G e-invoices	A.1128/2025 art. 2
30 Sep 2026	A.1197/2026 moves the second-period start from 1 Oct to 2 Nov 2026 and extends the parallel-use window to 31 Jan 2027	ΦΕΚ Β' 5905/30-09-2026
2 Nov 2026	Second period starts: remaining businesses must issue e-invoices; start declaration (provider or timologio) must name a start date no later than 2 Nov 2026	A.1128 art. 2 §2 as amended
2 Nov 2026 – 31 Jan 2027	Gradual fulfilment allowed: ERP or special entry form may still be used in parallel, if the declaration was filed on time	A.1197/2026
1 Feb 2027	Exclusive use of a licensed provider or AADE timologio / myDATAapp for covered invoices; ERP alone is no longer an issue channel	A.1128 / EY summary of the press release

AADE's English FAQ page carries the amended second-period date (02.11.2026). Always re-check aade.gr before you release.

What in-scope invoices look like

Topic	Rule	What to do in software
Scope (A.1128 art. 1)	Domestic wholesale B2B, B2B wholesale to third countries outside the EU (not retail), and B2G (public contracts and other General Government expenditure).	Do not treat every Greek invoice as in scope: retail B2C and intra-EU B2B are outside this decision. Keep a clear scope flag per counterparty and transaction type.
Issue channel (A.1128 art. 1 §2)	The e-invoice must be issued only through an AADE-licensed Electronic Tax Document Issuance Provider (ΥΠΑΗΣ) or through AADE's free timologio / myDATAapp. Ordinary ERP or commercial software is not an accepted issue channel by itself.	Integrate a licensed provider API, or guide small customers to timologio. Do not claim that 'ERP → myDATA SendInvoices' alone satisfies the e-invoice issue obligation.
myDATA transmission	Providers (and, where still allowed, ERP) post schema-conformant myDATA XML (InvoicesDoc / AadeBookInvoiceType) to the myDATA API. A successful call returns a MARK (unique registration number) and a QR URL.	Store MARK + authenticationCode on the invoice record; print the QR from the URL the service returns (providers: downloadingInvoiceUrl; ERP: qrCodeUrl).
Recipient download formats (myDATA v1.0.12)	Provider invoices must carry downloadingInvoiceUrl. The recipient can call it with /pdf (default), /myDATA (detailed myDATA XML) or /EN16931 (ELOT EN 16931).	Generate and store downloadingInvoiceUrl; use it for the printed QR. Offer or document EN 16931 download for EU buyers who need the European standard.
Receive obligation (A.1128 art. 2 §3)	From 2 March 2026, recipients in scope must accept e-invoices for domestic B2B and B2G covered by art. 1 (a) and (c).	Receiving systems must accept provider / timologio invoices; do not require a PDF-only path for those transactions.
Non-compliance	Failing to issue an electronic invoice is treated as failing to issue an invoice; Tax Procedure Code penalties apply (AADE FAQ).	Surface a clear 'not issued electronically' error before the user marks the invoice as sent.

Checklist for invoicing and ERP builders before 2 November 2026

Classify each customer and transaction: domestic B2B wholesale, non-EU B2B wholesale, B2G, or out of scope (retail, intra-EU B2B under this decision).
Pick at least one AADE-licensed provider API for issue, or a clear timologio hand-off for the smallest users. Treat ERP → myDATA as a temporary parallel path only through 31 January 2027.
File / support the “Declaration of Commencement of Electronic Issuance of Tax Documents” (A.1112/2025 art. 6) or the timologio use declaration with a start date ≤ 2 November 2026.
Persist MARK, uid, authenticationCode and the QR URL (downloadingInvoiceUrl or qrCodeUrl) on every transmitted invoice.
Expose EN 16931 download for recipients who need the European standard (/EN16931 on downloadingInvoiceUrl), and keep validating EN 16931 files you create yourself.
Accept inbound e-invoices for domestic B2B and B2G (receive obligation since 2 March 2026).
Block “sent as PDF only” for in-scope issue after the user's obligation date.

Example: create an EN 16931 Greek B2B invoice

Disclosure: W System, which publishes this page, makes the e-invoice API used below. Greece's myDATA wire format is the national InvoicesDoc schema, not Peppol. The call below creates a valid EN 16931 UBL invoice for placeholder Greek parties — the representation a recipient can pull with /EN16931 from a provider URL, and the format our free validator checks. It does not transmit to myDATA or obtain a MARK; that hop belongs to a licensed provider. Placeholder VAT numbers; not tax advice.

curl -X POST https://api.wsystem.dev/einvoice/create \
  -H 'Content-Type: application/json' --data @invoice.json

invoice.json:

{
 "format": "en16931",
 "invoice_number": "A-2026-0318",
 "issue_date": "2026-11-02",
 "due_date": "2026-12-02",
 "currency": "EUR",
 "buyer_reference": "PO-5521",
 "delivery_date": "2026-11-02",
 "seller": {
  "name": "Paradeigma Software M.IKE",
  "vat_id": "EL123456783",
  "street": "Odos Ermou 10",
  "city": "Athina",
  "postal_code": "10563",
  "country": "GR"
 },
 "buyer": {
  "name": "Pelatis A.E.",
  "vat_id": "EL987654321",
  "street": "Leoforos Tsimiski 20",
  "city": "Thessaloniki",
  "postal_code": "54624",
  "country": "GR"
 },
 "lines": [
  {
   "description": "Software subscription, November 2026",
   "quantity": 1,
   "unit": "C62",
   "unit_price": 200,
   "vat_rate": 24
  }
 ],
 "payment": {
  "iban": "GR1601101250000000012300695",
  "terms": "30 days"
 }
}

Real response from the live API on 19 October 2026 (the generated XML left out):

{
 "valid": true,
 "format": "en16931",
 "syntax": "UBL 2.1",
 "document_type": "ubl_inv",
 "totals": {
  "currency": "EUR",
  "line_total": "200.00",
  "vat_total": "48.00",
  "total_with_vat": "248.00",
  "payable": "248.00"
 },
 "errors": [],
 "warnings": [],
 "checked": {
  "xsd": true,
  "EN16931": true,
  "XRechnung": false,
  "PeppolBIS3": false,
  "SK_national": false
 },
 "notes": [],
 "disclaimer": "Technical check against the official EN 16931 / XRechnung rule sets. A technically valid file is not tax or legal advice. Peppol BIS 3 specific rules (PEPPOL-EN16931-*) are not checked yet."
}

To check files your own stack produces, drop them into the free e-invoice validator or call POST /einvoice/validate. GET /einvoice/route?id=EL… returns the curated Greek mandate row (phase A / phase B dates) alongside a Peppol Directory lookup — useful for cross-border, not a substitute for a provider registration. Free for 20 calls a day per IP; details on the e-invoice validation API page.

Questions and answers

Does every Greek business have to e-invoice from 2 November 2026?

Businesses with 2023 gross revenue over EUR 1 million have already been in the first period since 2 March 2026. From 2 November 2026 the remaining businesses (second period) must issue electronic invoices for the transactions in A.1128 article 1. Until 31 January 2027 they may still use ERP or the special entry form in parallel if they filed a start declaration with a start date no later than 2 November 2026. From 1 February 2027 only a licensed provider or AADE's timologio / myDATAapp may be used.

Is Peppol required in Greece?

No for this domestic mandate. Greece's clearance path is myDATA through a licensed provider or AADE tools. Peppol may still be used for cross-border or other voluntary cases, but A.1128 does not make Peppol the domestic channel. EN 16931 is available as a download representation via downloadingInvoiceUrl (/EN16931), not as the myDATA wire format.

Can my ERP keep sending invoices after 1 February 2027?

Not as the issue channel for in-scope invoices. After the transition, issuance and transmission to myDATA for covered transactions must go through a certified provider or AADE's applications. ERP may still prepare data and call a provider.

What is a MARK?

The unique registration number myDATA assigns when an invoice is successfully transmitted. It is filled by the service (along with uid and, for providers, authenticationCode). Keep it on the invoice and use the returned QR URL on the printed document.

Where do I read the official rules?

Joint decision A.1128/2025 (as amended by A.1197/2026 for the second-period dates), provider decision A.1112/2025, and the AADE English FAQ on mandatory electronic invoicing. Technical detail is in the myDATA API documentation for providers (SendInvoices) and the v1.0.12 notes on downloadingInvoiceUrl.

Sources

Checked against A.1128/2025 (codified with A.1197/2026), the AADE English FAQ and the myDATA v1.0.12 notes on 19 October 2026.

Facts checked 2026-10-19. W System is the maker of this product. Not affiliated with the European Commission. Not legal or tax advice.