If the building control work was carried out by your local authority, you should contact them to obtain a copy of a completion certificate or full plans approval notice.
Removing an internal wall without building regulations approval is sometimes possible, but it depends on the type of wall and its structural significance. Non-load-bearing walls, often called “stud walls,” are generally easier to remove without needing building regulations approval.
In the UK, obtaining a building permit requires submitting detailed plans of the proposed construction to the local council, including site plans, elevations, and sections. You must also comply with building regulations covering structural integrity, fire safety, energy efficiency, and access.
When building work has been inspected by suitably competent building control surveyors, with a completion certificate issued at the end, it means that as far as the surveyor is able to ascertain, the work done has complied with the building regulations.
If the building control work was carried out by your local authority, you should contact them to obtain a copy of a completion certificate or full plans approval notice.