Hi @RobRenshaw
Welcome to our Community Help Forum 🙂
Thank you for making your first post regarding the mobile signal in Clacton, I'm sorry to hear you cannot get 4G. It may be worth looking into these links for an idea of the status of the coverage in the local area;
For SIM cards supported by EE - https://coverage.ee.co.uk/coverage/ee
For SIM cards supported by Vodafone - https://coverage.ee.co.uk/coverage/ee
Best wishes,
Serena