We would like to remind you that the S/MIME certificate used for encrypting messages sent by participants to the relevant address in both the production and test environments has been renewed.

The new certificate is already available and runs in parallel with the current certificate, which expires on 6 June 2026.

If this type of communication applies to you, we recommend switching to the new S/MIME certificate as soon as possible.

• S/MIME PROD
• S/MIME SBX

We would also like to remind you that on 4 June 2026 at 15:00, the CS OTE Auth certificate will be renewed in the SBX test environment.

This change mainly affects participants using automated communication with CS OTE, especially via:

• SOAP web services,
• WS-Security,
• verification of response signatures,
• TLS authentication in the OTE → participant direction.

To maintain functional automated communication with CS OTE, we recommend verifying that the new certificate will be trusted and correctly processed in your systems.

• CS OTE Auth SBX

All necessary information regarding certificate configuration is available here:

https://www.ote-cr.cz/cs/registrace-a-smlouvy/pristup-do-cs-ote/konfigurace-pc

Thank you for verifying this in time and making the necessary updates.