To issue a domestic invoice correctly, it must contain the elements required by law, carry a unique sequential number, and be issued within the statutory deadline — in both Slovakia and the Czech Republic, within 15 days of the supply when you invoice another business. The details differ, though: Slovakia follows Section 74 of Act No. 222/2004, the Czech Republic Section 29 of Act No. 235/2004, and the thresholds for a simplified invoice are not the same.
Who must issue an invoice, and when?
In both countries the obligation falls on VAT payers. A Slovak VAT payer must issue an invoice under Section 72 of the VAT Act when supplying goods or services with the place of supply in Slovakia to another taxable person or a legal entity; a Czech payer has the same duty under Section 28 of the Czech VAT Act. In both cases the duty also arises when an advance payment is received before the supply.
Selling to an ordinary consumer generally does not trigger the VAT-law invoicing duty unless the customer asks. A non-VAT business is not obliged to issue an invoice under the VAT Act in either country, but still issues one as an accounting document to prove its income. If you would rather hand this over, our Slovak tax advisory can set your invoicing up correctly from the start.
What must the invoice contain?
The required elements are broadly similar but sit in different laws. A Slovak invoice under Section 74 must show the supplier and the customer with their VAT numbers, a sequential invoice number, the date of supply and the date of issue, the description and quantity of the goods or service, the tax base and unit price, the VAT rate applied (23 %, 19 % or 5 %) and the total VAT in euros.
A Czech tax document under Section 29 requires essentially the same set: identification of both parties and their tax identification numbers, an evidence (sequential) number, the scope and subject of the supply, the date of issue and the date of supply, the unit price and tax base, the VAT rate (21 % or 12 %) and the amount of tax in Czech koruna. A missing element is not a formality — without the data needed for a deduction, the customer may lose the right to deduct input VAT.
How should invoices be numbered?
Both legal systems require a unique number that unambiguously identifies the document but prescribe no fixed format. A continuous series without gaps, usually including the year, works well in practice. Do not change the numbering logic mid-year and do not skip numbers; if you cancel an invoice, its number stays in the series and the correction is made through a corrective document rather than by rewriting the original number.
By when must the invoice be issued?
The deadline is the same headline figure in both countries: 15 days. Slovakia (Section 73) counts it from the day of supply or the day an advance payment is received; the Czech Republic (Section 28) counts it from the date the taxable supply took place or the payment was received. In Slovakia this is a substantive deadline that does not shift when the last day falls on a weekend, so plan accordingly. Missing the deadline is a breach that the tax authority may penalise.
What are the payment terms?
Payment terms are a matter of contract, not VAT law, in both jurisdictions. If nothing is agreed, the debtor is in default after 30 days from delivery of the invoice, or from the supply if that is later. A term agreed between businesses generally may not exceed 60 days; a longer period is allowed only exceptionally and only where it is not grossly unfair to the creditor. State the due date explicitly so it is clear when late-payment interest starts to run.
When is a simplified invoice enough?
This is where the two systems diverge most. Slovakia allows a simplified invoice — without the customer’s identification and the unit price — up to 100 euros including VAT, or up to 400 euros for a cash-register or fuel-pump receipt. The Czech Republic allows a simplified tax document up to 10,000 CZK including VAT, which may omit the customer’s details, the unit price and the tax base. Neither can be used for distance sales or where the reverse charge applies.
An electronic invoice is equivalent to a paper one in both countries, provided the recipient agrees and the authenticity of origin, integrity of content and legibility are ensured. For the wider context of running a compliant back office, see our overview of professional accounting in Slovakia.
Which country’s rules should you follow?
The guiding principle is the place of supply: a supply located in Slovakia follows Slovak rules, a Czech supply the Czech ones. Never mix the two — Slovak thresholds and section numbers do not apply to a Czech invoice, and vice versa. When you operate in both markets, keep separate invoicing settings so the correct rate, threshold and mandatory fields apply to each.
Correctly configured invoicing saves you penalties and needless disputes with customers. We are happy to set up your invoices and numbering series so they meet the law and fit how you do business.
FAQ
Does a non-VAT business have to issue invoices?
Under the VAT Act, no — that duty applies to VAT payers. A non-VAT business still issues an invoice as an accounting document to prove its income for income-tax purposes, in both Slovakia and the Czech Republic. Such an invoice shows no VAT and no VAT number, only the price without tax.
By when must I issue an invoice?
Within 15 days in both countries. Slovakia counts the deadline from the day of supply (Section 73), the Czech Republic from the date the taxable supply took place (Section 28); if you receive an advance payment first, the 15 days run from that payment. In Slovakia the deadline is substantive and does not move if the last day is a weekend.
What is the threshold for a simplified invoice?
The threshold differs by country. Slovakia permits a simplified invoice up to 100 euros including VAT (or 400 euros for a cash-register or fuel-pump receipt). The Czech Republic permits a simplified tax document up to 10,000 CZK including VAT. In both cases certain details may be omitted, but the simplified form cannot be used for distance sales or the reverse charge.