B2G e-invoicing to the Greek public sector

E-invoicing in public procurement comes from Directive 2014/55/EU, which requires public bodies across the EU to receive and process electronic invoices that follow the European standard EN 16931. Greece transposed it in Articles 148 to 154 of Law 4601/2019.

The framework is completed by:

• decision 63446/2021, which sets the national data format, based on PEPPOL BIS 3.0,
• decision 98979 ΕΞ 2021 on how invoices are received and processed,
• decision 52445 ΕΞ 2023, which sets suppliers’ obligation and timetable, as amended by 182112/2024 and 100792 ΕΞ 2025.

The General Secretariat for Information Systems (ΓΓΠΣ) is Greece’s PEPPOL authority and runs the Interoperability Centre (KED) that invoices to contracting authorities pass through.

On top of this, Greece’s general mandatory e-invoicing (decision Α.1128/2025) also covers B2G transactions. From 1 February 2027, B2B and B2G invoices of businesses with revenue up to €1m can no longer be sent to myDATA from an ERP without a provider.

The obligation falls on economic operators, businesses and professionals, performing contracts with public bodies. What matters is when the award procedure started. After a pilot phase from 12 September 2023, it applies to contracts whose procedure started:

• from 1 January 2024, for all central government bodies,
• from 1 June 2024, for all other bodies awarding public contracts.

From 1 September 2025, it was extended to other spending by general government bodies that falls outside public procurement law.

Exempt, among others, are:

• low-value contracts with an estimated value up to €2,500 excl. VAT, and other spending up to €2,500,
• contracts between public sector bodies,
• service contracts between natural persons and general government bodies,
• contracts that started before the dates above and are still running.

The obligation is usually stated in the award decision or the contract. If in doubt, ask the contracting authority before you invoice.

A B2G invoice passes through four points:

• You, the supplier, issue the invoice in your software with the contract details.
• The certified provider converts it to the national format (PEPPOL BIS 3.0), marks it, sends it to myDATA and onto the PEPPOL network.
• KED routes it to the right recipient.
• The contracting authority receives it in its own system or, temporarily, through the ΕΔΗΤ application, checks it and proceeds to payment.

Status messages come back at each step, up to payment or rejection. So you know whether the invoice arrived, whether it was accepted and when it was paid, without phoning the body’s accounts office.

Like any other document, a B2G invoice is also sent to myDATA and receives a MARK, so it appears in your e-books as normal.

Suppliers without a Greek VAT number invoice through a certified PEPPOL access point.

B2G invoices are most often rejected because a contract detail is missing or wrong. Before the first invoice to a body, the General Secretariat recommends contacting it to confirm the routing details. You will usually need:

• the contracting authority’s code in the e-invoicing registry, so the invoice reaches the right recipient,
• the contract’s ΑΔΑΜ (its registration number in the central public contracts registry, ΚΗΜΔΗΣ),
• the ΑΔΑ of the budget commitment decision,
• the budget type funding the expense (regular budget, public investment programme, etc.),
• the contract details the national format asks for and, where requested, the CPV codes of the items.

Keep these on the public body’s customer record or with the contract, so you do not have to look them up for every invoice.

With public bodies, a rejected invoice usually means weeks of delay in getting paid. The most common problems are practical, not technical:

• Wrong recipient: one body may have several departments or units with different codes. Confirm the contracting authority code before the first invoice, and again if the department managing the contract changes.
• Missing contract details: an ΑΔΑΜ or ΑΔΑ that is missing or does not match the contract. Keep the details on the body’s customer record and update them when a new contract or amendment is signed.
• Amounts that do not match: prices, quantities or VAT that differ from the contract or the acceptance report. Invoice what was received, at the contract prices.
• A paper copy instead of an e-invoice: where the obligation applies, a PDF by email is not enough. The contracting authority must receive it through KED.
• Contracts outside the obligation: conversely, for exempt contracts, such as those up to €2,500 excl. VAT, ask the body how it prefers to receive the invoice.

When an invoice is rejected, the status message usually explains why. Correct it together with your accountant and the public body and resend, rather than waiting.

With eFluper’s connection to the certified e-invoicing provider Impact, you invoice public bodies from the same software you use for every other customer:

• the invoice is sent through Impact to the contracting authority,
• you see its B2G status on the document itself,
• you keep codes, units and CPV per product in your catalogue, so you never retype them.

The provider connection costs from €95 a year (excl. VAT), is available on every plan and also covers B2B invoices and retail. No special equipment and no printing needed.

Because the same connection also covers B2B invoices, when Greece’s general mandatory e-invoicing starts for your business (2 November 2026 for businesses with revenue up to €1m, with a transition until 31 January 2027) you need no second solution. Payments from the public body are recorded on its customer record, so you can see at any time which public sector invoices are still unpaid.