The Ministry of Interior has published recommendation for British citizens living in the Czech Republic. The Ministry recommends all UK citizens to apply for either Certificate of Temporary Residence if they intend to stay in the country for more than three months or for a Permanent Residence Permit if they have lived in the country for more than five years.
For further information please see the Ministry of Interior websites https://www.mvcr.cz/mvcren/article/immigration.aspx

Our experts are ready to assist you in case you wish to proceed according to the recommendation.