https://www.epo.org/en/service-support/faq/law-practice/unitary-patent/territorial-scope-unitary-patent-and-possible-0
What is the territorial scope of a Unitary Patent?
The geographical scope of the Unitary Patent will eventually cover all the 25 EU Member States that have joined the enhanced cooperation in the area of the creation of Unitary Patent protection. But to be covered by the Unitary Patent, a Member State must not only be participating in this enhanced co‑operation but must also have ratified the Agreement on a Unified Patent Court (UPCA) when unitary effect is registered. As of 1st September 2024, a total of 18 states have done so.
The geographical scope of a given Unitary Patent remains the same for its lifetime and is not extended to those states that ratify the UPCA after its unitary effect has been registered.