VAT Number Verification: How to Find and Verify a Tax Identification Number in the Czech Republic and Abroad

Quick Overview

• In the Czech Republic, you can verify a VAT ID primarily through the VAT payer registry, ARES, or the Trade Register.
• If you’re doing business with a partner from the EU, use the VIES system, which verifies the validity of VAT IDs for VAT purposes.
• For entities outside the EU, there is no single registry, so you must search the national databases of the respective country.
• An invalid or incorrectly stated VAT ID can complicate invoicing, VAT deductions, and potential tax audits.

Not sure if your invoice, VAT ID, or cross-border VAT is correct? Have our lawyers review your documents before the tax office gets involved.

What is a VAT ID and how does it differ from a company ID number

A VAT ID (tax identification number) is used to identify an entity to the tax authorities. In the Czech Republic, it consists of a country code (CZ) and an assigned number. For legal entities, the VAT ID is derived from the IČO, while for individuals, the birth number is typically used.

The IČO (Identification Number) is a different number assigned upon registration of a business. While the IČO is used in business transactions, the DIČ is essential for tax purposes and issuing tax documents.

Entrepreneurs often ask what a VAT ID is. It is the foreign equivalent of the DIČ, used within the European Union and essential for cross-border transactions.

How to Find a DIČ in the Czech Republic

If you need to find the DIČ of a company or an individual, there are several official sources available. Each is suitable for a slightly different situation, so we’ll go through them one by one.

One of the most common methods is to use the VAT payer registry on the Financial Administration’s website. Here, you can easily verify whether a given entity is registered for VAT and find its VAT ID at the same time. This registry is very reliable because the data comes directly from the tax authorities.

Another useful tool is ARES, the Administrative Register of Economic Entities, which is managed by the Ministry of Finance. In this register , you can search not only by business ID number but also by the entrepreneur’s name or company name. In the record details, you will often find the VAT ID as well, if the entity is registered for VAT. ARES is an ideal tool when you need a more comprehensive overview of a business—in addition to the VAT ID, you will also find information about the registered office, statutory bodies, or any changes in the entity’s history.

In practice, we often see that entrepreneurs only verify the IČO in ARES and automatically assume that this also verifies the DIČ. However, this may not be sufficient, especially when dealing with VAT. For business partners where invoicing affects VAT deductions or cross-border transactions, we recommend verifying the VAT payer registry or the VIES system directly and saving the results of the check.

If you are looking for the VAT ID of a natural person—a self-employed individual (OSVČ)— the Trade Register may also be useful. It contains information on all entrepreneurs with a trade license. While the VAT ID may not always be listed there, you will at least obtain the necessary information regarding the entrepreneur’s identity and existence, which will then help you locate the VAT ID later, for example through ARES.

If you’re wondering whether an invoice was issued correctly, whether you can claim a VAT deduction, or how to respond to a request from the tax office, it’s worth having a lawyer review your specific case.

VAT Number Verification Within the EU: The VIES System

If you do business with partners in the European Union, verifying VAT numbers is an absolute necessity. The VIES (VAT Information Exchange System) is used for this purpose— a unified European registry managed by the European Commission. Thanks to this system, you can verify within minutes whether your business partner is actually registered as a VAT payer and whether their tax identification number (VAT ID) matches the data in national registries.

VIES links the databases of all EU member states, making it a sort of “common search engine” for data on VAT payers. Its major advantage is that you don’t have to search through individual national registries—simply enter the data in one place, and the system will connect you to the relevant country’s database.

The check is therefore quick and free, but it is important to know that VIES is not a standalone registry. It merely retrieves data from national authorities, which means that information may occasionally be temporarily unavailable if a country experiences a technical outage.

From our experience: A client was providing services to a foreign company from the EU and relied solely on the VAT number listed in the email order. A later check revealed that the number was not valid for VAT at the time of service provision. The situation was only resolved after additional documentation was provided, but the client had to retroactively search for correspondence, orders, and evidence that they had verified the partner. This is precisely why we recommend saving the verification result from VIES for every significant transaction.

Step-by-step verification procedure:

1. Open the European Commission’s website, specifically the section dedicated to the VIES system.
2. In the drop-down menu, select the country where your business partner is based.
3. Enter their VAT number (without the two-letter country code) into the form.
4. Submit the query and wait for the verification result.

The system will show you within a few seconds whether the number is valid. In some cases, it will also provide basic information about the entity (such as the company name and registered address).

If the VIES system indicates that the VAT number is invalid, this does not always mean fraud. Sometimes it is a technical error or a delay in updating the databases. In such a case, it is a good idea to try verifying the number again later, check it directly in the national VAT payer registry of the specific country, or request official confirmation from your business partner.

Why verification via VIES is important

If you issue an invoice to a foreign partner and include an invalid VAT number on it, the tax authority may consider the transaction to be incorrectly reported. This has serious consequences:

• you cannot claim VAT exemption for supplies of goods or services to another member state,
• you risk being assessed additional VAT in the Czech Republic,
• and you may also face penalties or fines from the tax office.

Verifying the VAT ID via VIES is therefore not just a formality, but a crucial step in avoiding problems during a tax audit.

With cross-border transactions, the problem often lies in the details: a miscopied VAT ID, an unverified business partner, missing proof of verification, or an incorrectly issued invoice. For larger amounts, we recommend having the process reviewed in advance. A legal review is usually less expensive than subsequent VAT reassessment, penalties, or a dispute with the tax authorities.

Verifying a Tax ID Number in Slovakia

In Slovakia, the tax identification number (TIN) serves a slightly different purpose than it does here in the Czech Republic. It is used exclusively for income tax purposes and not for VAT. The format consists of ten digits, and the first two digits indicate the type of entity—for example, “10” denotes individuals, “20” denotes legal entities, and “40” denotes foreign companies registered in Slovakia. It is also important to note that a Slovak DIČ never begins with the prefix “SK.” That prefix appears only in the VAT ID, which is always different from the DIČ and is used to identify businesses for VAT payments.

So, if you ask a Slovak business partner for their tax ID number, you will receive a number that relates to income tax. However , if you need to determine whether the entity is a VAT payer, you must request their VAT ID number. This can then be verified through the European VIES system.

While each EU country uses its own tax identification system, the format of the VAT ID can vary significantly. For example, in Denmark it consists of several pairs of numbers, while in Italy it is an 11-digit number and may also include additional information about the company’s registered office. However, a common element for all countries is always the two-letter country code that precedes the numerical code. The unified VIES system is used to verify the validity of VAT numbers within the EU .

When dealing with a Slovak business partner, therefore, first clarify exactly what you need to verify. For income tax, the VAT ID is used, but for VAT, the VAT registration number is decisive. If your Slovak partner provides you with only a 10-digit VAT ID number without the SK prefix, this does not automatically mean that they are a VAT payer. For cross-border invoicing purposes, always request the VAT ID number and verify it via VIES.

Verifying Tax ID Numbers Outside the EU

If you do business with partners from countries outside the European Union, the situation is more complicated. There is no single international registry, so you must search directly in the databases of the respective country. This is usually a national tax payer registry, where you’ll find the equivalent of our VAT ID. The problem, however, is often the language barrier—not all registries have an English version, so you may sometimes need the help of a translator or a native speaker.

It is also good to keep in mind that some European countries are not members of the European Union and are not covered by the VIES system. Typical examples include Switzerland, Norway, Iceland, and Liechtenstein, where tax numbers must be verified in their own registries.

Summary

The Tax Identification Number (TIN) is a key piece of information for every entrepreneur and business, as it serves to uniquely identify them to the tax authorities and is essential for properly issuing invoices and claiming VAT. In the Czech Republic, the VAT ID is derived from the Company ID (IČO) for legal entities or the birth number for individuals, and it can be verified through the VAT payer registry, the ARES system, or the Trade License Registry. Within the EU, the VIES system is used to verify VAT IDs; it links the databases of member states and instantly verifies whether an entity is actually registered for VAT, which is particularly important for VAT exemptions on cross-border transactions. In Slovakia, the VAT ID is used only for income tax, while a separate VAT ID is used for VAT, and similar differences exist in other EU countries as well. If you do business outside the EU, you must search the national databases of individual countries.