Tax Identification Number (DIČ) on invoices – do I have to include it?

Tax Identification Number is not a mandatory detail on accounting documents, such as invoices, contracts, etc. (§ 10 of the Accounting Act).

This identifier (DIČ) is intended for communication with the tax authority.

This follows from § 67(7) of the Tax Administration Act (Act No. 563/2009 Coll. on Tax Administration and on amendments to certain laws), which states that the tax administrator assigns a tax identification number to a tax entity upon registration, provided that the conditions for registration under this act or special regulations are met; the tax entity is required to state this number when dealing with the tax authority.

If the entity is a VAT payer, they are subject to the obligation under § 74 of the VAT Act, where a mandatory component of an invoice includes, among other things, the VAT identification number (IČ DPH).

The elements that an accounting document must contain are listed in § 10 of Act No. 431/2002 Coll. on Accounting, as amended.

One of the required elements is the identification of the parties to the accounting transaction. The Accounting Act does not specify in detail what this identification must include. Therefore, from an accounting point of view, an entity may issue accounting documents even without an assigned DIČ.

Note also § 3a of the Commercial Code, which specifies what information every entrepreneur must include on their business correspondence and orders. According to this provision, business documents must contain the business name, registered office or place of business, legal form (for legal entities), company ID number (IČO) if assigned, and other information stated in this provision.

(Source: financnasprava.sk)