Your Czech Company's Data Box (datová schránka): the 10-Day Rule Foreign Owners Miss
Updated: 2026-08-14 · Tax year 2026. General information, not legal or tax advice. Confirm your company’s position with a Czech accountant or lawyer.
When your Czech s.r.o. is entered in the Commercial Register, the state opens a data box (datová schránka) for it automatically. You do not apply for it, you cannot decline it, and from that moment it is the channel the tax office, the Registry Court, the social security administration and the trade licensing office use to reach your company. Letters stop coming.
The part that catches foreign owners is § 17 of Act No. 300/2008 Coll.: if nobody logs in, a message is deemed delivered on the tenth day after it arrives. The deadline inside it then runs against a company that never read it. “We did not know” is not a defence anywhere in Czech administrative procedure.
What the data box actually is
It is a state-run electronic mailbox with legal effect equal to registered post. Since 1 January 2023 it exists mandatorily for:
- every legal entity registered in a public register, including every s.r.o. and every branch of a foreign company;
- every sole trader (OSVČ) with a trade licence;
- other legal entities such as associations and unit-owner communities.
Individuals who are not in business still have it voluntarily. Sending to public authorities is free; the box is not an email account and cannot receive ordinary mail.
The three rules that cost money
1. The 10-day delivery fiction. A message is delivered the moment an authorised person logs in — or, failing that, on the tenth day after it was placed in the box. From that day, appeal periods and payment deadlines run. A tax assessment nobody opened becomes final and enforceable exactly as if you had signed for it.
2. Messages disappear after 90 days. The content of delivered messages is deleted 90 days after delivery. The box is a delivery channel, not an archive. Download every message as a ZFO file or a printable PDF and store it with the company records, or activate the paid Datový trezor long-term storage. Owners who change accountants routinely discover that the entire correspondence history is gone.
3. Having a statutory data box makes electronic filing mandatory. Under § 72 of the Tax Code, a taxpayer with a data box established by law must submit form filings — corporate income tax returns, VAT returns, VAT control statements, registration forms — electronically in the prescribed format. File on paper and the submission is treated as defective: the tax office calls on you to fix it, and if you do not, a penalty of CZK 1,000 arises under § 247a, which can rise to CZK 50,000 where the failure seriously obstructs tax administration. The deadlines this applies to are set out in Czech s.r.o. tax filing deadlines for foreign owners.
Getting in when you do not live in Czechia
This is the practical bottleneck. Access credentials for the company box are issued to the statutory body — the jednatel — and sent by registered post to their address. If the managing director lives in Lisbon or Dubai, that envelope may take weeks or come back undelivered.
Your options, in order of how well they work for non-residents:
- Log in with credentials (username and password), then add two-factor authentication. Works from anywhere in the world, no Czech identity needed. This is the route most foreign directors end up using.
- Bank identity or Identita občana. Fast and convenient, but it presumes a Czech bank account with the right level of verification or a Czech ID document. See opening a bank account for a Czech company.
- Appoint an authorised person (pověřená osoba). The administrator of the box can give a named person — typically your accountant or lawyer — rights to read and send messages. Rights can be limited by message type and withdrawn at any time. This is the correct answer for a company whose owner does not read Czech.
Whatever you pick, switch on notifications. Email notification of a new message is free and turns the 10-day fiction from a trap into a non-issue.
What arrives in it
- Registry Court — calls to file the annual accounts in the Collection of Deeds, and the fines and dissolution warnings that follow if you ignore them. See filing your Czech s.r.o. annual accounts.
- Tax office — assessments, calls to remedy defects, notices of tax inspection, VAT registration decisions.
- ČSSZ and health insurers — payroll-related notices once you have staff, as covered in hiring your first employee.
- Trade Licensing Office and courts — licence matters, litigation.
Anything with a deadline arrives here. Nothing important arrives anywhere else.
A five-minute setup checklist
- Activate the box within days of incorporation — do not wait for the first message.
- Add a second login method and enable two-factor authentication.
- Turn on email notifications to an address that at least two people monitor.
- Grant your accountant an authorised-person role with defined rights.
- Set a monthly reminder to export new messages before the 90-day clock runs out.
- Keep the company’s registered office and contact details in the Commercial Register current — you can verify what is published using the method in how to check a Czech company.
Frequently asked questions
Can I keep receiving paper letters instead?
No. For an entity with a statutory data box, authorities deliver electronically. Paper is used only when electronic delivery is not possible.
What if the 10th day falls on a weekend?
The message is still treated as delivered. What may shift is the deadline that runs from delivery, under the general rules on counting time limits. Do not plan around it — plan around reading the box.
I dissolved the company. Does the box close automatically?
It is disabled once the entity is deleted from the register, but obligations that arose before that remain. Keep exported messages after the company is gone.
Does the data box replace an accountant?
No. It delivers documents in Czech, mostly in a formal register style, and many of them start a deadline the same day. Reading them is the easy part; knowing which ones matter is not.
Can two directors have separate access?
Yes. Each statutory representative gets their own credentials, and the administrator can add further authorised persons with individual rights.
Do not let a message expire unread
The most expensive administrative failures we see in Czech companies are not complicated — they are a court call sitting unopened in a data box while the owner is abroad. Our accounting services for Czech companies include monitoring the data box, flagging anything with a deadline and filing electronically on the company’s behalf. If you are still at the setup stage, the whole sequence is covered in company formation in the Czech Republic.