Plenty of hosts are wary of the data box (datová schránka) — and yet it is the most useful thing the state has ever set up for you. Notifying a trade, a tax return, an application for UbyPort access, a report to the municipality: all from the sofa, with a delivery receipt and free of charge.

Two things matter. You have the box even if you do not know about it. And the post in it counts as served even if you never read it. The defence takes twenty minutes and costs nothing — just beware, the portal moved house in 2026.

What to do

You most likely have a box already

Since 1 January 2023 the state has set up a box free of charge for every self-employed person as soon as it learns of their entry in a statutory register (§ 4 (1) of Act no. 300/2008 Coll.), and for every legal entity in the register of persons (§ 5 (1)), associations and owners' associations included. The only ones who do not get one automatically are entrepreneurs without an IČO and foreign persons.

The credentials do not come by registered post but into the addressee's own hands exclusively (§ 10 (1)) — not even a spouse may take them. The collection period is 10 days, and uncollected credentials are invalidated. And above all: the box is activated by the first login, and no later than on the 15th day after the credentials are delivered (§ 10 (2)). So a box you have never set foot in is alive too.

More convenient than a username and password is Identita občana (bank identity, an eID card, the eGovernment Mobile Key, NIA ID, MojeID). The old mojedatovaschranka.cz has merely redirected since 27 August 2026, so the password saved in your browser has to be entered again. And since 1 August 2026 you can only get into the Citizen Portal with Identita občana.

The fiction of service — the only real danger

A document is served at the moment an authorised person logs in (§ 17 (3)). If nobody logs in within 10 calendar days of the day of delivery, it is served on the last day of that period (§ 17 (4)), with the effects of service into your own hands. A payment assessment, a call from the fee administrator, a summons: the deadlines run whether you read them or not. Hence „served“, not „read“.

The same fiction applies to messages from private senders (§ 18a (3)): a lawyer's pre-action notice or a reminder from the owners' association is served after ten days just the same. Moreover, all boxes are set to receive them from the outset, and under the ISDS operating rules only the holder of a natural person's box may switch that off — an entrepreneur may not.

Twenty minutes of setup, step by step

1. 1Log in at datovka.gov.cz — with Identita občana, or with the username and password from the envelope.
2. 2Turn on e-mail notifications: Settings → Notifications → E-mail notifications. They are free.
3. 3Rewrite the filters in your mail client: notifications come from notifikace@datovka.gov.cz, previously from notifikace@mojedatovaschranka.cz. Without that you have them switched on and still know nothing about them. The content of the message does not travel in them.
4. 4Install the eGovernment Mobile Key, pair it with a QR code (Settings → Login options → Login with the Mobile Key) and turn on push: Settings → Notifications → Notifications to the Mobile Key. Free, unlike SMS at CZK 3 including VAT per message.
5. 5With an s.r.o., add your accountant as an authorised person: Settings → Users → New user. The managing director has access (§ 8 (3)), an authorised person acts within the scope assigned to them (§ 8 (6)) and receives their own credentials — never give anyone yours.

What you can settle from the sofa

An act performed through the data box has the same effects as an act performed in writing and signed (§ 18 (2) of Act no. 300/2008 Coll.) — you need no electronic signature.

• THE TRADE LICENCE — notification, changes, business premises and suspension through the unified registration form (JRF) from rzp.gov.cz. → How to set up a trade licence for accommodation: step by step in one afternoon
• TAXES — the return, the registration application and the notice of a change of registration details are form filings, and with a box held by operation of law you must make them electronically only (§ 72 (1) and (6) of Act no. 280/2009 Coll., as in force from 1 January 2026). The MOJE daně portal (mojedane.gov.cz) also works — the DIS+ tax information box or the EPO application at adisspr.mfcr.cz.
• THE FOREIGN POLICE — you generate the application to register an accommodation facility in the UbyPort application (ubyport.pcr.cz/UbyPort) and send it to the box of the Directorate of the Foreign Police Service, ybndqw9. Reporting guests then runs in UbyPort, not through the data box. → UbyPort without the stress: how to report foreign guests to the foreign police correctly
• THE MUNICIPALITY — the notification for the stay fee and the regular reports. In Prague: notification within 30 days of starting the activity, changes within 15 days, a rate of CZK 50 per person and commenced day excluding the day of arrival, remittance by the 15th day of the following month (Prague General Binding Decree no. 18/2019 Coll.). Elsewhere according to the municipality's decree. → Stay fee: every municipality sets it differently — and you are the one collecting it
• THE ČSSZ AND YOUR HEALTH INSURER — the overviews for the self-employed are not an option but a duty, and a PDF into the data box will not do. With a box held by operation of law you file the ČSSZ overview in XML only (the ČSSZ ePortal or box 5ffu6xk); from 1 January 2026 the VZP accepts the overview electronically only, and from all self-employed persons, not just box holders (Moje VZP, a VZP Point, box i48ae3q).
• REGISTRATION OF SHORT-TERM RENTALS — nowhere for now. European Union Regulation 2024/1028 applies from 20 May 2026, but as of 5 September 2026 Czechia has neither an adapting act nor a register, and eTurista is to run only in 2027. → Airbnb in Czechia, legally: the complete map of a host's obligations

Messages to authorities and receiving messages are free; what you pay for are postal data messages to private recipients — CZK 10 including VAT up to 20 MB, CZK 30 above 20 MB (Czech Post price list from 1 April 2026). The attachments of one message may total up to 100 MB (since 1 January 2024, previously 20 MB) and besides PDF, DOCX, XLSX, JPG, PNG, XML and ZIP will pass too (Decree no. 194/2009 Coll.).

What survives 90 days and what does not

Messages are deleted, and that is not a habit but a firm rule: they are stored for 90 days from the day an authorised person logged in, and for 3 years from the day of delivery if nobody logs in (§ 6 of Decree no. 194/2009 Coll.).

What does not disappear: the ISDS keeps message envelopes without attachments permanently, in the History folder. Years later you can still download the delivery receipt of a deleted message there as a PDF or ZFO with the current seal of the ISDS administrator, or have it converted into paper form at a Czech POINT. The content and attachments, however, are not kept, and searching is possible only within a three-month interval. Go through Sent items for the content and History for the proof — in a dispute about a deadline the delivery receipt is your evidence.

You save the content yourself and free of charge: the DOWNLOAD MESSAGE (ZFO) button saves the envelope and the attachments as electronically signed data, and the second option is the Archive service in the Citizen Portal — free, but you have to switch it on in your data box settings (a copy of the message is created three weeks after service). The paid Data Vault of Czech Post costs CZK 120 a year for 20 messages and CZK 3,300 for 500 messages (price list from 1 April 2026, including VAT). When the box is set up you also get the Data Vault on trial once — 20 messages for 3 months free. A saved PDF attachment has no evidential value on its own.

The most common mistakes and myths

• „I never collected the credentials, so I have no box.“ — You do. It is activated no later than on the 15th day after the credentials are delivered (§ 10 (2)). A dead box into which calls keep dropping is the most expensive way of ignoring things in Czech law.
• „Notifications used to come, so I have it sorted.“ — Since 27 August 2026 they come from notifikace@datovka.gov.cz. Your old filters will stop catching them.
• „The fiction of service applies only to authorities.“ — It does not. Messages from private senders are served after 10 days just the same (§ 18a (3)) and an entrepreneur cannot switch off receiving them.
• „I'll send the self-employed overview into the data box as a PDF.“ — They will not accept it. The ČSSZ wants XML; from 1 January 2026 the VZP wants Moje VZP, a VZP Point or box i48ae3q.

Frequently asked questions

Updated: 5 September 2026, verified against the sources listed above. This is informational text, not legal or tax advice — consult a professional about your specific situation.