You issue an invoice and type a due date into the field without thinking too hard about whether 7, 14, or 30 days is correct. Most self-employed people (OSVČ, osoba samostatně výdělečně činná — the standard Czech legal status for a freelancer or sole trader) just follow habit, or whatever their invoicing tool suggests. The law, in fact, does not prescribe a due date length at all — but it has very clear rules for what happens once a client pays late.
This article gives you concrete recommendations by client type, the correct way to calculate a due date, and exactly how much extra money a client owes you if they pay late. It reflects the rules in force in the Czech Republic in 2026 for domestic business-to-business invoicing.
What Czech law actually says about invoice due dates
The Czech Civil Code (občanský zákoník) does not set a required length for an invoice due date. If two businesses have not agreed on one, Section 1963(1) makes the price due within 30 days:
- from the day the client received the invoice,
- from the day the goods were delivered or the service was provided, if it cannot be established when the invoice arrived, or if it arrived before you delivered,
- from the day of acceptance or verification that you delivered properly, if the contract or the law requires one and the invoice arrived earlier — typically a handover protocol or acceptance of the work.
If you leave the due date off the invoice and agree nothing else with the client, this statutory 30-day period simply runs automatically. The acceptance or verification itself may take longer than 30 days from delivery only if that is expressly agreed and not especially disadvantageous to you (Section 1965).
A longer due date can be agreed, but between businesses there is a limit. A due date of more than 60 days is valid only if it is expressly agreed and not especially disadvantageous to you as the creditor (Section 1963(2)). Under Section 1964, a payment-term clause that is especially disadvantageous to the creditor is invalid — even for a shorter period. A court looks mainly at the nature of the job, whether there is a fair reason for the long period, and whether it goes against business custom and fair dealing. If it declares the clause invalid, the statutory rules apply instead. In practice, a large client can propose 90-day terms, but without a real reason such a clause can be challenged.
If you invoice a public contracting authority (for example a ministry, a region, a municipality or one of their organisations), the same 30 days apply. A longer due date must be expressly agreed, justified by the nature of the contract and no longer than 60 days (Section 1963(3)).
These rules have applied since 6 January 2023 (amending Act No. 374/2022 Coll.). If you read elsewhere that a due date is "ineffective" when it is "grossly unfair", that describes the older wording of the law.
For a consumer client (a B2C relationship), the due date is mainly a matter of agreement; if nothing is agreed, payment is due without undue delay after being requested.
The statutory 30-day period is a safety net for situations where you forget to state a due date or never explicitly agreed on one. Relying on it is not ideal, though — a clearly stated date on the invoice avoids later disputes about when the clock actually started, and from when any late-payment period is calculated.
How many days to give each type of client
In practice, it works best to choose a due date based on who you are billing, not one fixed rule for your whole account.
| Client type | Recommended due date | Watch out for |
|---|---|---|
| Individual, small job | 7–14 days | A shorter period speeds up payment; the risk of late payment is usually low |
| Small company, repeat client | 14 days | Check their payment history on the first few invoices |
| Mid-size company, standard B2B | 30 days | Matches the statutory default and is what most clients expect |
| Large corporate client with its own payment policy | 30–60 days | Above 60 days only if expressly agreed and with a real reason; otherwise ask for an upfront deposit |
| Public authority, municipality, state organisation | 30 days | A longer due date only if expressly agreed, and never over 60 days |
| New client with no track record | Deposit upfront, or a shorter due date | Reduces your risk on the first job |
Whichever option you choose, agree the due date with the client clearly and in advance — a vague "pay whenever you can" only leads to misunderstandings later and makes the debt harder to collect.
Example: the same freelancer, two different due dates
A graphic designer trading as Anna Example works for two very different types of client at once. For a corporate client, Company XYZ, she issues a monthly invoice for design work with a 30-day due date — that matches the statutory default and the approval process larger companies typically run internally before paying. For a small individual client ordering a one-off logo, she gives a 10-day due date and, since it is their first job together, asks for half the price upfront as a deposit.
Both invoices are perfectly correct even though they carry different due dates — the law does not require one uniform period across every document a single self-employed person issues. What matters each time is the actual agreement with that specific client, not one blanket rule for the whole business.
How to calculate the due date correctly
If the invoice states a due date you agreed with the client, that date applies. The statutory 30 days are counted under the rules above — most often from the day the client actually received the invoice. If you email an invoice immediately after issuing it, the issue date and delivery date are effectively the same. With a delayed delivery or a printed document, a gap of a few days can arise.
The due date on an invoice and the date of taxable supply (DUZP, den uskutečnění zdanitelného plnění) are two separate pieces of information and should never be confused. DUZP determines which VAT period the supply belongs to; the due date only tells the client when to pay. This distinction, and how a Czech sole trader's tax point interacts with the actual payment date, is covered in more depth in our companion article on when a Czech sole trader taxes an invoice.
If the last day of the due-date period falls on a Saturday, Sunday, or a public holiday, it moves to the next working day under Section 607 of the Civil Code. When you are counting the exact day a payment becomes overdue, always check the calendar, not just the date's day-of-month number.
What to do the day after the due date
One day of late payment is not yet a crisis, but it is a reason to act. A workable approach is a polite reminder right after the due date, a more formal reminder after a week or two, and — for a long-outstanding invoice — a final pre-legal reminder that clearly states the amount owed plus interest. Chasing dozens of invoices manually, whether in your head or in a notebook, is the main reason self-employed people put reminders off. Once you can see an invoice's status at a glance and a reminder goes out automatically, unpaid amounts stop slipping through the cracks.
For a persistently difficult client, it is worth tightening the terms going forward — a shorter due date, an upfront deposit, or card payment at the time of ordering. That client's own payment history is a far better guide than one general rule applied to every job.
Late payment interest: how much, and how to calculate it
Between businesses, late payment automatically triggers statutory interest for late payment under Government Regulation No. 351/2013 Coll. The rate is the Czech National Bank's (ČNB) repo rate valid on the first day of the half-year, plus 8 percentage points. For a late payment that begins in the second half of 2026, that comes to 11.75% a year (with a 3.75% repo rate); in the first half of 2026 it was 11.50% a year.
The calculation itself is simple: multiply the amount owed by the annual rate, divide by 365 days, and multiply by the number of days late.
10,000 CZK × 11.75% / 365 × 30 days = 96.58 CZK ≈ 97 CZK
For one month of late payment on an invoice for 10,000 CZK, the client owes roughly an extra 97 CZK. On top of that, the supplier is entitled to compensation of at least 1,200 CZK per claim for the costs of collecting the debt, regardless of what those costs actually were (§ 3 of Government Regulation No. 351/2013 Coll.). It applies between businesses and towards public contracting authorities. Interest starts accruing the day after the due date, and the right to claim payment of the debt itself generally becomes time-barred after 3 years.
For comparison, on an invoice for 50,000 CZK with 45 days of late payment: 50,000 CZK × 11.75% / 365 × 45 days = 724.32 CZK, so roughly 724 CZK. The higher the amount owed and the longer the delay, the more the interest actually adds up — it is not just a symbolic penalty you can safely ignore.
Due dates and taxes: what they affect, and what they do not
The due date on its own does not determine your taxes. For an OSVČ keeping Czech cash-basis tax records (daňová evidence), taxable income only arises when an invoice is actually paid, regardless of the due date printed on the document. An invoice issued in December with a January due date, paid only in February, becomes income in February — nothing else.
For a VAT payer, the obligation to declare VAT follows DUZP, not the due date and not the actual payment. An invoice with a 30-day due date can have a DUZP on the day it was issued — and it is that date, not the due date, that VAT is reported against.
Example: a self-employed person issues an invoice on 20 December 2026 with a 14-day due date, i.e. due by 3 January 2027, and the client pays on the very last day. For a non-VAT-registered OSVČ keeping cash-basis tax records, that income falls into 2027, even though the invoice itself was issued back in December 2026 — the payment date decides, not the issue date or the end of the due-date period.
How to track due dates without doing the math yourself
A due date only needs to be set once as a default for new invoices, then adjusted per job when needed. Three things help in practice: an overview of overdue invoices in one place, a QR payment code with a prefilled Czech variable symbol (variabilní symbol, a payment reference number) that shortens the time it takes a client to pay, and a web invoice — a public link showing the current payment status. Details on how the public web-invoice link works are covered in our article on the web invoice public link.
For invoices reconciled against actual bank activity, it also helps to know how your invoicing tool actually matches an incoming payment to an open invoice — see our companion guide on connecting invoicing to your bank for how that matching typically works and where it can fail.
Combining a default due date, QR payment, and automatic reminders means you do not have to scroll through your invoice list every day counting down to each due date by hand — the system only flags something when it is actually time to act.
How Taxorio handles this
In Taxorio's settings you can set a default invoice due date (14 days after you register), and change it for any individual invoice at any time. An invoice carries a QR payment code with a prefilled variable symbol whenever you have a bank account in the invoice's currency, and can also be sent as a web invoice — a public link showing live payment status that works even over WhatsApp or text message.
The Pro plan additionally tracks overdue invoices and can send automatic reminders in a cascade of up to five steps — the default is 3 days before the due date, then 3 and 14 days after, with the option to adjust the timing manually for any single invoice. The main reminders toggle lives in Settings under Reminders. You can try this in Taxorio's Free plan without a credit card.