An open registry with one Czech-shaped catch
CZ.NIC is an association of legal entities, not a state body and not a commercial registry group, and it has run .cz since 1998 alongside work such as the FRED registry software and the Turris routers. The registration rules reflect that engineering-led culture: they are short, published in full, and they set no eligibility test whatsoever. Any person or company anywhere can be a holder, and registration is immediate.
The catch is not about who may register but about how the name is written. .cz supports no internationalised domain names at all: a name may contain only the letters a to z, the digits 0 to 9 and hyphens, up to 63 characters. Czech has a diacritic-heavy orthography, so a brand written with hacky or carky has to be transliterated to register, and the transliterated form is the one your customers will type. Decide which spelling is the canonical one before you print it, not after.
The 60-day protection period, and where names go afterwards
The .cz expiry sequence is more forgiving than a gTLD's at the start and sharper at the end. On the day after expiry the name enters a protection period of 60 days, and for the first 30 of those it remains delegated: mail and the website keep working while the renewal is sorted out. If it is still unrenewed after 30 days, CZ.NIC is entitled to end the delegation, and the rules are explicit that a delegation ended this way cannot be restored by changing or reassigning the nameserver set. Renewal remains possible for the whole 60 days and applies retroactively from the expiry date, so you do not lose the paid period. On day 61 the registration expires and the rights to the name expire with it.
What happens next changed in May 2024. Released .cz names used to be caught within seconds by automated dropcatching services; CZ.NIC now routes them into its own auction system, where bidders verified through MojeID or an EU eID compete for a priority right to register the name. For a buyer this cuts both ways: a name you let go may cost real money to get back, and a name you have been waiting for is at least obtainable without operating a dropcatcher. Either way, the practical advice is the same one the protection period implies — renew inside the first 30 days, while the site is still up.