If the electrician used was registered with a government-approved scheme, you should contact them.
Answered by Dave, Electrical Safety Expert
It is important that you receive a certificate for electrical work carried out on your property. The certification is provided to the person who ordered the work. If the electrician used was registered with a government-approved scheme, you should contact them if the electrician will not provide you with the certificate. If they weren't registered, they will be unable to supply you with a certificate so you will need to contact your local authority building control who will advise you the next steps. If you do not have the correct certificate for major electrical work, you may find it difficult to sell your property.
It is the home owner's responsibilty to inform building control before you carry out major electrical work, unless you use an electrician registered with a government-approved scheme, as they can self-certify the work and provide you with the right certification.