IČO, DIČ, IČ DPH — Slovakia's three identifiers

Slovakia maintains three distinct identifiers to identify an economic entity: the IČO (8 digits, legal organisation identifier issued by ŠÚ SR via the RPO register), the DIČ (tax TIN issued by FRSR, 10 digits), and the IČ DPH (EU-VIES VAT, format SK + 10 digits). Mixing the three is one of the most frequent errors in Slovak EDI / e-invoicing integrations.

History — from Czechoslovak system to 1993 split

The Slovak IČO is a direct legacy of the Czechoslovak Socialist Republic (ČSSR), where the Identifikační číslo organizace was unified in the 1980s. After the "velvet divorce" on 1 January 1993, both states kept the same 8-digit format and the same control algorithm (modulo-11 checksum). That is why PEPPOL uses the ICD 0143 shared by SK and CZ: historically IČOs were common. Since 1993, allocations have been distinct (ŠÚ SR registries for SK, ČSÚ for CZ).

text ico-dic-icdph-format.txt

IČO       = 8 digits (NNNNNNNN)
            Issued by Štatistický úrad SR (ŠÚ SR)
            RPO register (Register právnických osôb)
            Same format as CZ IČO (Czechoslovak legacy 1989)
            Example: 12345678
            PEPPOL: ICD 0143
            Lookup URL: https://rpo.statistics.sk/

DIČ       = 10 digits (NNNNNNNNNN)
            Issued by Finančné riaditeľstvo SR (FRSR)
            National tax identifier, no prefix
            Mandatory on invoices
            Example: 2012345678
            Lookup URL: https://www.financnasprava.sk/sk/elektronicke-sluzby/verejne-sluzby/zoznamy

IČ DPH    = SK + 10 digits (SKNNNNNNNNNN)
            Issued by FRSR upon VAT registration
            EU VIES VAT format
            Pre-validatable on ec.europa.eu/vies
            Example: SK2012345678
            PEPPOL: ICD 9914 (EU VAT)
            Lookup URL: https://ec.europa.eu/taxation_customs/vies/

Governance — ŠÚ SR, FRSR, MS SR

Three authorities manage the Slovak identifiers:

Štatistický úrad SR (ŠÚ SR) (statistics.sk) — assigns the IČO via the RPO register (Register právnických osôb, podnikateľov a orgánov verejnej moci). Also coordinates the SK NACE classification.
Finančné riaditeľstvo SR (FRSR) (financnasprava.sk) — issues the DIČ at tax registration, and the IČ DPH upon VAT registration. Maintains the public DPH taxpayer directory.
Ministerstvo spravodlivosti SR (MS SR) (justice.gov.sk) — operates the Obchodný register (commercial register), which records companies (s.r.o., a.s., etc.); commercial-register registration triggers IČO assignment via ŠÚ SR.

Technical schema — formats and checksum

The three identifiers follow strict, verifiable formats:

Identifier	Format	Checksum	Example
IČO	NNNNNNNN (8 digits)	Modulo 11 over the first 7 digits	12345678
DIČ	NNNNNNNNNN (10 digits)	Modulo 11, FRSR algorithm	2012345678
IČ DPH	SK + NNNNNNNNNN (12 chars)	= SK + DIČ + VIES validation	SK2012345678

Comparison with EU neighbours

Country	Legal ID	Tax ID	EU VAT ID	Main PEPPOL ICD
Slovakia	IČO (8 digits)	DIČ (10 digits)	SK + DIČ	0143
Czechia	IČO (8 digits)	DIČ (CZ + 8-10 digits)	CZ + DIČ	0143
Poland	NIP (10 digits)	NIP = TIN	PL + NIP	9931 (NIP)
Hungary	Adószám (11 digits)	Adószám	HU + first 8 digits	9910
Austria	FN (commercial register)	UID (ATU + 8 digits)	UID = ATU+8	9915
Germany	HRB (commercial register)	USt-IdNr (DE + 9 digits)	USt-IdNr	9930

Adoption — PEPPOL and VIES usage

~700,000 entities in the RPO register (companies, non-profits, sole traders — ŠÚ SR 2024 figure).
~250,000 active IČ DPH registrations (businesses above the EUR 49,790 threshold), VIES-validatable.
PEPPOL usage: ICD 0143 (IČO) is the primary routing identifier in BIS Billing 3.0 invoices (B2G and B2B PEPPOL). ICD 9914 (EU VAT) is recorded in cac:PartyTaxScheme/cbc:CompanyID.
VIES usage: systematic cross-border validation for intra-EU supplies — major tax control point, REST validation available on ec.europa.eu/vies.

Common pitfalls

Swapping IČO and DIČ. IČO (8 digits) is used for routing and legal identification. DIČ (10 digits) for tax. Mixing them in PartyIdentification breaks PEPPOL routing or makes the invoice invalid.
Forgetting SK on IČ DPH. IČ DPH must always carry the SK prefix for VIES. Putting just 10 digits in cbc:CompanyID makes the VAT non-validatable cross-border.
Confusing with CZ. A Czech company also has an 8-digit IČO and a DIČ — but IČOs have been re-allocated separately since 1993. A Czech IČO is not recognised by the Slovak RPO register.
Believing ICD 0143 = automatic SK. ICD 0143 covers both SK AND CZ IČOs. To disambiguate, the country code in the address (Country/IdentificationCode = SK) is crucial. Otherwise the receiver may route to the wrong jurisdiction.
Not checking the RPO. The public RPO register (rpo.statistics.sk) enables real-time IČO validation. Skipping this step before issuing a large invoice exposes you to a rejection or fraud (dissolved entity).

Foundations

Standards

Flagship messages

Tools