In brief
- The DIČ is a ten-digit tax identification number; it is not in the commercial or trade register.
- It is published together with the company ID in the Financial Directorate's list of subjects with a tax reliability index, and in the Register of Financial Statements.
- If a company has a VAT ID, the DIČ is usually the same number without the SK prefix.
- From 1 January 2027 you need it for e-invoicing — invoices are addressed by DIČ, not by company ID.
You know a company's IČO from its invoices, contracts and the business register. Its DIČ — the tax identification number — is harder to find, although from January 2027 every e-invoice will need it. Here is where to find it and what to watch for.
IČO, DIČ and IČ DPH are different numbers
- IČO is the eight-digit company ID. It appears in the commercial, trade and legal-entity registers.
- DIČ is the ten-digit tax identification number, assigned by the Financial Administration on registration for income tax.
- IČ DPH is the VAT ID. Only VAT-registered subjects have one; a Slovak VAT ID is SK followed by ten digits — usually the same as the DIČ.
Why the DIČ is not in the business register
Neither the commercial register nor the trade register lists the DIČ — it belongs to the Financial Administration, not the registry court or trade office. It need not appear on business correspondence either: the law requires the business name, registered office and IČO there. That is why your records often lack it even for a long-standing partner.
Where to find it
Under § 52(17) of the Tax Procedure Code, the Financial Directorate publishes the list of taxable subjects that have been assigned a tax reliability index. Each entry carries both DIČ and IČO — the file we loaded on 20 September 2026 held 649,016 subjects, nearly all of them with an IČO. The public list of accounting entities in the Register of Financial Statements carries both numbers too (§ 23(7) of the Accounting Act). We look the DIČ up in the Financial Administration's list.
If a company has a VAT ID, you can usually read the DIČ off it by dropping the SK prefix. Anyone not registered for VAT has no VAT ID, so for most sole traders and small companies that route does not work.
Why the DIČ matters from 2027
On Peppol, e-invoices are delivered to an address of the form 0245:DIČ — not by IČO. Your invoicing software will need the DIČ of every customer a VAT payer invoices electronically from 1 January 2027. If your records lack it, fill it in before 1 January 2027.
A subject without a DIČ cannot receive an e-invoice. The Financial Administration advises it to apply for income tax registration — a DIČ is issued within 30 days of the application.
When you cannot find it
- The company is younger than two to three years. A business receives its tax reliability index — and with it an entry in the list — only two years after the end of the year it registered for income tax. Such a company is in the list of subjects registered for income tax, which the Financial Directorate publishes under § 52(14) of the Tax Procedure Code.
- The subject has no DIČ, as with some non-profit organisations.
- The IČO is mistyped or missing its leading zeros — a Slovak IČO has eight digits.
In that case the safest route is to ask the customer. For bulk lookups, our API returns the DIČ for a hundred company IDs at once.