A registered electrician will be able to advise you on the certification you need
Answered by Rupert, Electrical Safety Expert
A registered electrician will be able to advise you on the certification you need. You can find one local to you here.
If the fan that is being installed in your bathroom requires a new circuit to be added then this work is notifiable under Part P of the Building Regulations and would need a certificate to be issued to confirm the work complies. If it is being added to an existing circuit then this would not be necessary.
We would expect to see a Minor Works Certificate issued for the fan but just an invoice/work order for a new light.
Landlords in England and Scotland are required to have the installation in their rental properties checked every five years* and we recommend that landlords in Wales and Northern Ireland also have these checks completed. You can find more information and advice here.
* This will also be a legal requirement in Wales from July 2022.