Invoice requirements in Czechia — what a tax document must contain

An invoice is the most common document a company issues — and one of the few whose content is set not by habit but directly by law. When a mandatory detail is missing, it is not a mere formality: on a tax document, an incorrect or incomplete invoice can jeopardise the customer's right to deduct VAT, and at an audit this is usually the first thing the tax authority looks at.

Czech law distinguishes two cases. If you are a VAT payer, you issue a tax document, whose details are listed precisely in Section 29 of Act No. 235/2004 Coll., on value added tax. If you are not a payer, you do not issue a tax document within the meaning of the VAT Act and you show no VAT on the invoice — yet your invoice is still a business document and an accounting record with its own mandatory details. This overview explains what belongs on each type of invoice, what a simplified tax document is, and by when documents must be issued and kept.

What a VAT payer's tax document must contain

A full tax document under Section 29 must contain this complete set of details:

• identification of the person making the supply (the supplier) and their tax identification number (DIČ);
• identification of the person to whom the supply is made (the customer) and their DIČ;
• the serial number of the tax document;
• the scope and subject of the supply (what is supplied and how much);
• the date the document is issued;
• the date of the taxable supply (DUZP), or the date a payment is received, if it differs from the issue date;
• the unit price excluding tax and any discount;
• the tax base, the tax rate and the amount of tax — and the tax is always stated in Czech currency.

Two details cause the most errors in practice. The first is the DUZP: the date of the taxable supply determines which tax period the tax belongs to, and need not be the same as the invoice issue date. The second is the amount of tax in korunas — even if you invoice in euros or another currency, the tax itself must be converted and stated in CZK on the document. Whether your supply is subject to VAT at all and which rate to use is something we covered in our article on how VAT works in Czechia for a small business.

A non-payer's invoice — fewer details, but the rules still apply

If you are not a VAT payer, the VAT Act does not govern your invoice — there is no VAT on it and the words "tax document" do not belong there. That does not mean the invoice can look like anything. As a business document under Section 435 of the Civil Code it must contain your name or company name, your registered seat or place of business, your company number (IČO) and details of your entry in a public register (for example the commercial or trade register), including the file number, if you are registered there.

At the same time the invoice is an accounting record, so it must be clear what was supplied, to whom, for how much and when. In practice a non-payer's invoice therefore carries almost the same identifying and substantive details as a tax document — it simply omits the VAT fields.

A simplified tax document up to CZK 10,000

For smaller amounts the law makes issuing easier. If the total amount for the supply does not exceed CZK 10,000 including tax, a simplified tax document may be issued under Section 30. It need not contain the customer's identification and DIČ, nor the tax base and tax amount shown separately — the total amount the seller received for the supply is enough. A typical example is an ordinary till receipt.

There is a catch on the customer's side, though: to claim a VAT deduction, they must fill in the missing details (above all the amount of tax) themselves and be able to document them. For purchases from which you plan to deduct, it therefore pays to ask straight away for a full tax document.

By when to issue an invoice and how long to keep it

A VAT payer must issue a tax document within 15 days of the date of the taxable supply (or of receiving a payment, if it precedes the supply). And documents must be archived for a long time — the VAT Act requires keeping them for at least 10 years from the end of the tax period in which the supply took place. Electronic invoices are fully equivalent to paper ones; what matters is preserving the authenticity of origin and legibility throughout the retention period.

Common mistakes and why the details matter

The most common problems arise not from bad faith but from carelessness: a missing or incorrect customer DIČ, a forgotten serial number, a wrongly set DUZP, or tax not stated in korunas. On an ordinary invoice you fix this with a corrective document, but for a VAT deduction it can mean delay and even a dispute with the tax authority. Check the customer's identifying details before issuing — you can verify both the IČO and the validity of the DIČ free of charge in the ARES register and the VAT payers register.

Special rules apply to invoicing abroad, where further details come in such as the reason for exemption or the reverse-charge regime — we looked at these in our article on invoicing abroad from a Czech company.

Conclusion

Invoice requirements are not bureaucracy for its own sake — they decide whether a document stands up at an audit and whether the customer can deduct from it. A payer watches the full list under Section 29, a non-payer the identifying details of a business document, and both the timely issue and the ten-year archiving. Keeping your documents in order from the first invoice is as natural as the address in a carefully run house for just thirty companies.

Frequently asked questions

What must an invoice contain if I am not a VAT payer?

A non-VAT payer does not issue a tax document and shows no VAT on the invoice. The invoice is, however, a business document under Section 435 of the Civil Code, so it must contain your name or company name, your registered seat or place of business, your company number (IČO) and details of your entry in a public register, including the file number. As an accounting record it must also make clear what you supplied, to whom, for how much and when.

Up to what amount can a simplified tax document be issued?

Up to a total of CZK 10,000 including tax. A simplified tax document under Section 30 need not contain the customer's identification and DIČ, nor the tax base and tax amount shown separately; the total amount for the supply is enough. If the customer wants to claim a VAT deduction, however, they must add and document the missing details, so ask for a full tax document for such purchases.

How long must I keep invoices?

Under the VAT Act, tax documents must be kept for at least 10 years from the end of the tax period in which the supply took place. A payer must also issue a tax document within 15 days of the date of the taxable supply. Electronic and paper documents are equivalent, but their authenticity and legibility must be preserved.