How to issue an invoice correctly in 2026: A guide for entrepreneurs

Invoicing is daily bread for every entrepreneur, whether you are self‑employed (OSVČ) or a company. In 2026 strict rules still apply to what an invoice must contain to be a valid accounting document.

Mistakes on invoices can lead not only to issues with the tax office, but also to your customer returning the invoice and you waiting longer for payment.

What must an invoice contain? (Required items)

The Accounting Act and the Civil Code define the basic requirements that must not be missing from any invoice:

1. Supplier and customer identification: Full name (or company name), registered address (or place of business) and company ID (IČO).
2. Document designation: For example "Invoice No. 2026001". The number must be unique within the accounting period.
3. Subject of supply: Description of the goods or services you invoice. Be specific (e.g., "Website development" instead of just "Services").
4. Amount: The total amount due.
5. Issue date: The day the invoice was issued.

Tip: Don’t forget to include the due date, even though it is not legally required. It clearly defines when you expect payment.

Are you a VAT payer? Additional obligations apply

If you are registered for VAT, your invoice becomes a tax document and must include additional details:

• VAT IDs (DIČ) of supplier and customer (if the customer is also a VAT payer).
• Date of taxable supply (DUZP).
• Tax base, tax rate and tax amount in Czech currency.

Electronic invoicing is the standard

In 2026 paper invoices are rather rare. Most entrepreneurs use online tools that generate a PDF invoice and send it by email. It is faster, cheaper, and more eco‑friendly.

Our invoice generator helps you create a professional document in a minute and keeps all mandatory fields in check.