Getting permission to leave a tenancy
Tenants should try to negotiate with their property manager if they are unable to continue the tenancy. The landlord will often try to come to a mutually acceptable way of ending the tenancy. The landlord may agree to release the tenant from the contract if a replacement tenant can be found or if the tenant agrees to cover the costs of advertising the property and listing it with an agent. Once the terms of the surrender have been agreed it’s important for the tenant to have a copy of the release and any associated conditions in writing and signed by the property manager.
https://www.housingrights.org.uk/news/can-tenant-leave-property-tenancy-agreement-expires
https://daily.wordreference.com/2021/04/29/basic-word-of-the-day-leave/