Uniform List of Blocked Websites: Simplification for ISPs
As of 1 January 2026, the Czech Telecommunication Office (CTO) is publishing a new Uniform List of Blocked Websites, which centralizes all websites to which Internet service providers (ISPs) are obliged to block access under other legal regulations.
The aim of this regulation is to create a single unified list of blocked websites available in one place, thus simplifying orientation in the area of blocked websites. The Uniform List of Blocked Websites does not replace the existing lists, but brings simplification in the form of a uniform, publicly available, and machine-readable list.
Legal developments in a nutshell
- The new Section 115b of the Electronic Communications Act (Act No. 127/2005 Coll.) imposes an obligation on the CTO to publish the Uniform List of Blocked Websites in a manner allowing remote access and establishes the obligation of the relevant authorities to transmit to the CTO data on entries and deletions from their source lists, which these authorities maintain under other legal regulations.
- The implementing decree on the transmission of data to the Uniform List of Blocked Websites (Decree No. 569/2025 Coll.) regulates the scope of published data (URL address, date of entry and date of deletion, identification of the relevant authority maintaining the source list and the name of the dataset), the conditions for transmitting data from the source lists of the relevant authorities to the CTO (including transmitting data by 8:00 p.m. on the day the change was published in the source list), and detailed technical specifications of the data files.
- The Uniform List of Blocked Websites is available here: External link
Existing ISP blocking obligations
According to the relevant legal regulations, ISPs are obliged to block access to websites that have been included in the relevant list of blocked websites by the relevant authorities, and to restore access after the websites are deleted from the relevant list. Currently, the following lists are maintained in the Czech Republic:
- List of illegal online games of chance: External link
List maintained by: Ministry of Finance
Obligation to block access: within 15 days of publication
Obligation to restore access: within 15 days of deletion
- List of websites with dangerous food products: External link
List maintained by: State Agriculture and Food Inspection
Obligation to block access: within 15 days of publication
Obligation to restore access: within 7 days of deletion
- List of websites with illegal medicinal products: External link
List maintained by: State Institute for Drug Control
Obligation to block access: within 15 days of publication
Obligation to restore access: without undue delay after deletion
- List of websites with illegal veterinary medicinal products: External link
List maintained by: Institute for State Control of Veterinary Biologicals and Medicaments
Obligation to block access: within 15 days of publication
Obligation to restore access: without undue delay after deletion
Practical implications for ISPs
- Monitoring a single list: The Uniform List of Blocked Websites reduces the administrative burden and allows ISPs to continuously monitor only one list.
- Uniform format: ISPs will be able to use a uniform format and thus avoid the need to deal with the formats of individual source lists, which simplifies automated processing.
- Process setup: ISPs can adjust their internal processes to take advantage of the benefits of monitoring only the Uniform List of Blocked Websites.
Conclusion
The Uniform List of Blocked Websites is a practical innovation that does not introduce new obligations for ISPs or new categories of blocked websites, but simplifies orientation in blocked websites under other legal regulations, thus bringing administrative simplification in fulfilling ISP obligations.
If you are interested in the topic of electronic communications and want to learn more, please contact your CMS client partner or our regulatory expert Jan Ježek.
