In which countries do you provide Hosted by 3CX?

Hosted by 3CX is available for customers in the following countries: https://www.3cx.com/support/hosting-service/.
This doesn't imply that the hosted instance will be operated in the same country you residing in.

European customers will be located within the EEA. Currently, we utilize datacenters in
Germany and the Netherlands. 

Customers located in Great Britain and Northern Ireland will utilize a datacenter in England.