AFM + GEMI — Greek business identifiers

Two numbers identify a Greek business. The AFM (Arithmos Forologikou Mitroou, "tax registry number") is the 9-digit tax number with a check digit — the equivalent of a company tax/VAT ID. The GEMI (Geniko Emporiko Mitroo, "general commercial registry") is the commercial registration number. For e-invoicing and myDATA it is the AFM that serves as the key: identifying the issuer, the customer, and — prefixed EL — the intra-Community VAT number.

History — from the tax file to GEMI

The AFM became universal in the 1990s as the single tax identifier of any person (natural or legal) with obligations in Greece. On the commercial side, Greece long had fragmented registers kept by the local chambers of commerce. Law 3419/2005 creates GEMI to unify them, then Law 4635/2019 modernises it (online procedures, one-stop shop, interconnection with the European BRIS registry).

1990s      | The AFM (Arithmos Forologikou Mitroou) becomes universal — a
           | unique 9-digit tax number assigned to every natural or legal
           | person with tax obligations in Greece.
           |
2005       | Law 3419/2005 — creation of GEMI (Geniko Emporiko Mitroo), the
           | general commercial registry, to unify the registers kept by the
           | local chambers of commerce.
           |
2011-2015  | GEMI ramps up as the single business registry; the GEMI number is
           | distinct from the AFM, tied to commercial registration.
           |
2019       | Law 4635/2019 — overhaul and modernisation of GEMI (online
           | procedures, one-stop shop, interconnection with the European BRIS).
           |
2021       | myDATA relies on the AFM as the identification key for the issuer
           | and the counterpart (customer) in every transmitted invoice.
           |
2023-2026  | B2G/B2B e-invoicing: the AFM becomes the routing and VAT identifier
           | (EL prefix), with a dedicated PEPPOL ICD code for Greece.

Governance — AADE + GEMI + chambers

The AFM is assigned and managed by AADE (the Independent Authority for Public Revenue) through the tax offices (DOY). GEMI is operated under the Ministry of Development, with the chambers of commerce (Epimelitiria) running the local desks. A business first obtains its AFM (tax) then its GEMI number (commercial) on registration — both numbers coexist throughout the company's life.

Schema — AFM, checksum, EL, PEPPOL ICD

The AFM carries a check digit computed with powers-of-2 weights, which lets you catch a typo before even contacting AADE. Here is the structure and the algorithm, plus the VAT-prefix and PEPPOL routing rules:

AFM — structure and check (9 digits)
====================================
  Format: 9 digits, e.g. 0 9 4 0 1 9 0 1 7
  - first 8 = identifier
  - 9th = check digit

Check-digit algorithm (powers-of-2 weights)
-------------------------------------------
  sum = d1*256 + d2*128 + d3*64 + d4*32
      + d5*16  + d6*8   + d7*4  + d8*2
  rem = (sum mod 11) mod 10
  check = d9 must equal rem

Example: 09401901[7]
  d1..d8 = 0,9,4,0,1,9,0,1
  sum = 0*256 + 9*128 + 4*64 + 0*32 + 1*16 + 9*8 + 0*4 + 1*2
      = 0 + 1152 + 256 + 0 + 16 + 72 + 0 + 2 = 1498
  1498 mod 11 = 2 ... (illustrative example — verify on real cases)

Intra-Community VAT
-------------------
  GR VAT = prefix "EL" + AFM   (e.g. EL094019017)
  WARNING: the VAT prefix is EL, not GR — a classic trap.

PEPPOL / e-invoicing
--------------------
  The AFM serves as the party identifier (issuer.vatNumber in myDATA)
  and routing key, with a PEPPOL ICD scheme specific to Greece.

AFM vs GEMI — which role

Usage — invoice, myDATA, PEPPOL

• myDATA: the AFM fills the issuer.vatNumber and counterpart.vatNumber fields of every invoice transmitted to AADE.
• Intra-EU VAT: EL + AFM, verifiable via VIES for cross-border transactions.
• PEPPOL: the AFM serves as the party identifier with a PEPPOL ICD scheme specific to Greece, for B2G / B2B routing.
• GEMI: appears in legal mentions and the invoice header, and feeds the European interconnection of registries (BRIS).

Common pitfalls

• Prefixing VAT with GR. The correct prefix is EL. It is the most common Greece integration error.
• Confusing AFM and GEMI. The AFM is the tax key (invoice, myDATA); the GEMI is commercial. Putting the GEMI in the vatNumber field breaks reconciliation.
• Not validating the check digit. A mistyped AFM can look fine but fail the modulo-11 check — validating upfront avoids myDATA rejections.
• Dropping the leading zero. Some AFMs start with 0; numeric storage that truncates the zero yields an invalid identifier.
• Ignoring VAT status. A business may hold an AFM without being VAT-registered (special regime); do not assume EL + AFM = active VAT.

Cross-links

• Greece hub — full view
• myDATA — electronic books
• VAT (FPA) regimes
• B2G mandate — accredited providers
• B2B mandate 2025-2026
• AADE — tax administration
• GEMI — business registry
• VIES — EU VAT validation