The tax identification number (TIN) is an essential piece of information for every entrepreneur and company. It can be found on invoices, in accounting and in business transactions at home and abroad. The correct TIN is important not only for legal obligations but also for the correct application of value added tax (VAT). If you use an incorrect or non-existent TIN on an invoice, you risk not only tax penalties but also non-recognition of the right to deduct VAT.
A TIN (tax identification number) is used to identify an entity to the tax administration. In the Czech Republic, it consists of a country code (CZ) and an assigned number. In the case of legal entities, the TIN is derived from the registration number, while in the case of natural persons, the birth number is usually used.
The IČO (personal identification number) is a different number assigned when registering a business. While the ID number is used in business transactions, the TIN is key for tax purposes and issuing tax documents.
Often, business owners ask what a VAT ID is. It is the foreign equivalent of a VAT number, which is used within the European Union and is essential for cross-border transactions.
If you need to find out the VAT number of a company or individual, there are several official sources available to you. Each one is suited to a slightly different situation, so we’ll go through them in turn.
One of the most common ways is to use the VAT register on the Financial Administration website. Here, you can easily check if the entity in question is registered for VAT and also find out its VAT number. This register 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 name of the entrepreneur or the name of the company. In the details of the record you can often find out the VAT number if the entity is registered for VAT. ARES is the ideal tool when you need a more comprehensive overview of the entrepreneur – in addition to the VAT number, you will also find information about the registered office, statutory bodies or any changes in history.
If you are looking for the VAT number of a natural person – entrepreneur (self-employed), the Trade Register may also be useful. This contains data on all entrepreneurs with a trade licence. Although the VAT number may not always be listed here, you will at least get the necessary information about the identity and existence of the entrepreneur, which will then help you to find the VAT number later, for example via ARES.
Do you need advice on checking your VAT number, invoicing abroad or legal disputes with the Tax Administration? Our lawyers can help you quickly, clearly and online.
If you are trading with partners in the European Union, TIN verification is an absolute must. This is done through the VIES (VAT Information Exchange System), a single European register managed by the European Commission. It allows you to check in a few minutes whether your business partner is actually registered for VAT and whether his tax identification number (VAT ID) matches the data in the national registers.
VIES connects the databases of all EU Member States, so it is a kind of “common search engine” for VAT payers. Its great advantage is that you do not have to go through the individual national registers – you just have to enter the data in one place and the system will connect you to the database of the relevant country.
The check is therefore quick and free, but it is important to know that VIES is not a separate register. It only receives data from national administrators, which means that sometimes data may be temporarily unavailable if a country has a technical failure.
Step-by-step verification procedure:
The system will show you within a few seconds whether the number is valid. In some cases, it will also add basic information about the entity (for example, the company name and registered office address).
If the VIES system shows that the VAT number is not valid, 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 to verify the number again later or to check the number directly with the national VAT register of the particular country, or to ask for official confirmation from the business partner.
If you issue an invoice to a foreign partner and include an invalid VAT number, the tax authorities may consider the transaction to be incorrectly reported. This has serious consequences:
Verifying your VAT number via VIES is therefore not just a formality, but an essential step to avoid problems during tax control.
Tip: Should you pay VAT for an unreliable payer? We advise you how to defend yourself.
In Slovakia, the tax identification number (TIN) has a slightly different role than in the Czech Republic. The format is ten digits and the first two digits indicate the type of entity – for example, “10” indicates natural persons ,“20” legal entities and “40” foreign companies registered in Slovakia. It is also important that the Slovak VAT number never starts with the prefix “SK”. This appears only with the VAT number, which is always different from the VAT number and is used to identify businesses when making VAT payments.
Therefore, if you ask for the VAT number of a Slovak business partner, you will get a number that relates to income tax. However, if you need to find out whether the entity is a VAT payer, you need to ask for its VAT number. This can then be verified through the European VIES system.
Although each EU country uses its own tax identification system, the format of the VAT number can vary considerably. For example, in Denmark it consists of several pairs of numbers, in Italy it is 11 digits and may include additional information about the company’s registered office. However, the common element for all countries is always a two-letter country code preceding the numeric code. The uniform VIES system is used to verify the validity of the VAT number within the EU .
If you are trading with partners from outside the EU, the situation is more complicated. There is no single international register, so you have to search directly in the country’s databases. This is usually the national taxpayer register, where you can find the equivalent of our VAT number. However, the problem is the language barrier, as not all registers have an English version, so sometimes you cannot do without the help of a translator or native speaker.
It is also good to remember that some European countries are not members of the European Union and are not covered by the VIES system. Typical examples are Switzerland, Norway, Iceland or Liechtenstein, where you need to verify tax numbers in their own registers.
Tip: The VAT deduction is a key tool for entrepreneurs and companies to avoid burdening their business with a tax that should be passed on to the end consumer. Do you know when you can claim it and what the catches are?
The tax identification number (TIN) is a key piece of information for every entrepreneur and company, as it serves to uniquely identify them to the tax administration and is essential for the correct issuance of invoices and the application of VAT. In the Czech Republic, the TIN is derived from the corporate ID number or the birth number of individuals and can be obtained through the VAT register, the ARES system or the trade register. Within the EU, the VIES system is used to verify the VAT number, linking the databases of the Member States and verifying in an instant whether an entity is actually registered for VAT, which is particularly important for VAT exemption in cross-border transactions. In Slovakia, the VAT number is used only for income tax, while a separate VAT number is used for VAT, and similar differences exist in other EU countries. If you are trading outside the EU, you need to search the national databases of each country.
Just use the ARES system or the VAT register.
For self-employed persons, the VAT number is usually derived from the birth number and the prefix CZ.
VAT ID is the European designation for the VAT number used for VAT within the EU.
Visit the European Commission website, enter your VAT number and country of registration, and the system will check.
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