ERP and accounting software for Greece: myDATA, e-invoicing

Greek compliance in one view

Keeping the books of a Greek business now means issuing B2B and public-sector invoices only as electronic invoices through a licensed provider or AADE's timologio application, reporting every document to myDATA, and filing VAT returns monthly or quarterly. Larger entities have been in scope since 2 March 2026 and everyone else joins on 1 October 2026. It matters because the invoice route itself is regulated.

Tax administration is run by the Independent Authority for Public Revenue (AADE, also written IAPR in English). Its myAADE portal hosts returns and registrations, and myDATA holds the electronic books that increasingly drive pre-filled returns. Social security for employees is administered by e-EFKA, to which employers submit the Analytical Periodic Declaration (APD) electronically.

This page sets out the e-invoicing timeline as of September 2026, VAT rates including the island rates, the other digital reporting streams, and what Skyline Nexus ERP covers for a Greek business today and what is being rolled out.

• Tax authority: AADE, through myAADE and myDATA
• Currency: euro; standard VAT rate 24%
• E-invoicing: mandatory in two phases, 2 March and 1 October 2026
• Accounts: Greek Accounting Standards (Law 4308/2014)
• Payroll reporting: APD to e-EFKA

The e-invoicing timeline as of September 2026

Article 14 of Law 4308/2014, the Greek Accounting Standards law, gained a new paragraph through article 239 of Law 5222/2025, and joint decision A.1128/16.09.2025 (Government Gazette B 4937) set the scope and dates. Invoices must be issued exclusively in electronic form for three kinds of sale: domestic supplies to another entity subject to Law 4308/2014, wholesale supplies to businesses outside the EU, and supplies under public contracts or other general government expenditure.

The first phase covers entities whose gross revenue in their 2023 income tax return exceeded 1,000,000 euro. It was due to start on 2 February 2026; decision A.1044/17.02.2026 (Government Gazette B 880) moved it to 2 March 2026, with a transition to 3 May 2026 during which invoices could still be issued from business software and transmitted to myDATA, or issued manually and entered through AADE's special entry form, provided the entity had declared the start of electronic issuance on time. From 2 March 2026 recipients in scope must accept electronic invoices.

The second phase covers all other entities from 1 October 2026, with a transition from 1 October to 31 December 2026 on the same conditions, and no exception from 1 January 2027. We are reporting the dates as set in the published decisions as of September 2026; professional bodies have asked for more time and AADE has moved dates before, so confirm the current position before planning a cut-over.

• Legal basis: article 14 of Law 4308/2014; decision A.1128/2025
• Phase 1: 2023 gross revenue above 1,000,000 euro, from 2 March 2026
• Phase 1 transition: to 3 May 2026
• Phase 2: all other entities from 1 October 2026
• Phase 2 transition: to 31 December 2026
• Scope: domestic B2B, B2B with non-EU businesses, and B2G

Providers, timologio and the recipient's side

A Greek electronic invoice is not simply a PDF sent by e-mail. AADE decision A.1112/01.08.2025 (Government Gazette B 4206) sets the obligations of licensed providers of electronic issuing services, the licensing of their software, and a self-provider route for businesses that meet the conditions themselves. The entity files a declaration that it issues through a provider or self-provider, and the provider authenticates each document and transmits its data to myDATA.

The alternative is timologio, AADE's free application for issuing and transmitting documents, also offered as the myDATAapp mobile application, which suits businesses with low invoice volumes. Ordinary business software, including an ERP, is not itself an accepted way to issue the e-invoice: it prepares the data, and the provider or timologio issues the document. Whichever route is used, the invoice data reaches myDATA at issue, so the supplier's and the customer's books are fed from the same record.

For the buyer, the change is just as real: invoices in scope must be accepted in electronic form, and purchase classification in myDATA has to match what suppliers transmitted. AADE circular E.2004/13.02.2026 gives guidance on fines for non-compliance, and decision A.1129/2025 sets declarations linked to income tax incentives for using e-invoicing.

VAT rates, island rates and returns

Greece applies a 24% standard rate, in force since 1 June 2016, a 13% reduced rate and a 6% super-reduced rate. AADE lists examples: the 13% rate covers basic foods such as bread, milk, meat, fish and olive oil, and services such as tourist accommodation and restaurants; the 6% rate covers medicines, books, newspapers, theatre and concert tickets, electricity and natural gas. Annex III of the VAT Code is the authoritative list.

On five islands, Leros, Lesvos, Kos, Samos and Chios, the three rates are reduced by 30%, to 17%, 9% and 4%, following a ministerial decision.

VAT returns are filed for every tax period whether the result is payable, refundable or zero. Entities keeping double-entry books file monthly; those on single-entry books, or not obliged to keep books, file quarterly. The return and payment are due by the last working day of the month after the period, and a timely return with tax above 100 euro can be paid in two equal instalments. A credit balance can be carried forward or claimed as a refund.

• 24% standard, 13% reduced, 6% super-reduced
• 17%, 9% and 4% on Leros, Lesvos, Kos, Samos and Chios
• Monthly returns for double-entry books; quarterly for single-entry
• Due by the last working day of the month after the period

myDATA: electronic books and pre-filled returns

myDATA is the platform through which entities transmit invoice and receipt data and the classification of income and expenses to AADE, under decision A.1138/2020 issued under article 15A of the Code of Tax Procedure. Each transmitted document is recorded in the entity's electronic books, and both sides of a B2B transaction appear there.

The practical effect has grown every year. According to the European Commission's country profile, VAT returns have been pre-filled from myDATA data since 1 January 2024 and income tax returns since 2025. A ledger that classifies income and expenses differently from what was transmitted to myDATA therefore creates reconciliation work at every return.

Two further digital streams sit alongside it. Goods movement documents are being moved to digital issue with transmission to myDATA under decisions A.1122/2024 and A.1123/2024, with later phases rescheduled by AADE decisions in April 2026. Card terminals have been linked to cash registers, with the Ministry of National Economy and Finance reporting more than 430,000 connections by late 2024.

Public sector invoicing, accounts and payroll

Invoices to public bodies follow EN 16931 using Peppol BIS Billing 3.0 and are routed through the National Interoperability Centre by Peppol service providers. After a phased start, electronic invoicing for general government expenditure became mandatory on 1 September 2025, with limited exemptions, according to the joint press release of the ministries involved.

Greek entities prepare financial statements under the Greek Accounting Standards of Law 4308/2014, which sort entities into size categories that decide the content of the statements and whether a statutory audit is required. Groups with securities listed on an EU regulated market use IFRS as adopted by the EU in their consolidated accounts under Regulation (EC) 1606/2002.

Employers submit the Analytical Periodic Declaration of pay and contributions electronically to e-EFKA, the unified social security body, and withhold income tax on salaries for AADE. The ledger therefore needs separate liabilities for social security contributions and withheld tax, reconciled to what is actually paid.

Cities and regions: where the rules differ

E-invoicing, myDATA and VAT returns are national, so a business in Athens, Thessaloniki, Piraeus, Patras, Larissa, Volos or Ioannina works under the same phases and deadlines. The one regional difference in this page's obligations is the island VAT rate.

Businesses on Leros, Lesvos, Kos, Samos and Chios apply rates of 17%, 9% and 4% in place of 24%, 13% and 6%. The reduction applies only on those five islands, so Crete, with Heraklion and Chania, and Rhodes use the standard national rates. A company with a warehouse in Thessaloniki and a shop in Mytilene on Lesvos therefore needs separate tax codes by location, and its e-invoices must carry the rate that applies where the supply is made.

• Mainland and most islands: 24%, 13% and 6%
• Leros, Lesvos, Kos, Samos, Chios: 17%, 9% and 4%
• Everywhere: the same e-invoicing phases and myDATA reporting

Preparing for 1 October 2026

A business that joins in the second phase has a short list of decisions to make. First, the issuing route: a licensed provider that connects to the business's own system, self-provider status, or timologio for low volumes. Second, the declaration to AADE of the start of electronic issuance, on time, because the transition relief depends on it. Third, master data: every customer's tax number, correct tax codes per line and the myDATA income classification for each revenue type.

On the purchasing side, the business must be able to receive electronic invoices, match them to purchase orders and goods received, and classify expenses consistently with what suppliers transmit. The finance team should run a month of parallel reconciliation between the ledger and the myDATA electronic books before the transition ends on 31 December 2026.

How Skyline Nexus ERP handles Greek requirements

Skyline Nexus ERP is a cloud ERP with a double-entry general ledger under Fiscal Authority. When the auto-post switches are on, final sales, purchases, payments, expenses and depreciation post balanced journals in the background, with VAT computed per line. Each VAT rate is its own tax rate, so island and mainland rates sit side by side and the right one is applied on each line. The VAT Return screen prefills tax-exclusive bases and VAT for a date range, which a bookkeeper compares with the pre-filled return in myAADE.

Posted journals are corrected by reversal, fiscal periods can be closed and locked, and an Accounting Audit Trail records changes with old and new values, user and time. Business locations carry their own invoice numbering, stock and a branch-filtered trial balance, profit and loss and balance sheet, useful for a company with a warehouse in Thessaloniki and a shop on Lesvos. The trial balance, general ledger and a yearly Audit Pack workbook export to Excel for the accountant and the auditor.

National e-invoicing connectors are being rolled out market by market, and for Greece that programme covers issuing through a licensed provider with myDATA transmission and digital delivery notes: tell us your country and we will confirm your go-live date. Until then, invoices are issued through a licensed provider or timologio and brought into the ledger with Import Sales, which previews each batch and can revert it. Greek payroll and the APD run in local payroll software or through a payroll partner, with the monthly journal posted to the ledger.

Rates, regimes and deadlines in this summary change, and many countries are actively legislating on e-invoicing. This is general information, not tax or legal advice — confirm the current position with the authority named above or with your tax adviser before you rely on it.