The problem is getting a scheme to accept you, if the work you are doing does not need notifying then you don't need any qualification, the trade had ordinary, instructed, skilled, and competent person, the competent was dropped.
Skilled person. A person with technical knowledge or sufficient experience to enable him/her to avoid dangers
which electricity may create.
Competent person. A person who possesses sufficient technical knowledge, relevant practical skills and
experience for the nature of the electrical work undertaken and is able at all times to prevent danger and, where
appropriate, injury to him/herself and others.
The Part P or other laws depending where you live vary, in Wales the kitchen is a special location, in England it isn't.
The new English landlord laws state "“qualified person” means a person competent to undertake the inspection and testing required under regulation 3(1) and any further investigative or remedial work in accordance with the electrical safety standards;"
Anything you repair or install should have a minor works or installation certificate or a portable appliance test completed, so C&G 2391 covers testing and inspection of the installation, and C&G 2377 for the PAT testing actually called "The inspection and testing of in-service electrical equipment" and comes in two parts, the actually testing and inspecting and the management of the results.
The new landlord law in England has caused a small problem with definitions "“consumer’s installation” means the electric lines situated upon the consumer’s side of the supply terminals together with any equipment permanently connected or intended to be permanently connected thereto on that side;" the IET does not include current using equipment as part of the installation with the exception of the lights, so an EICR would have stopped at the fused connection unit, or socket, and the inspection and testing of in-service electrical equipment would have taken over at that point.
However now it seems the inspector must also look at any fixed equipment, boilers, immersion heaters, even the washing machine unless fitted with wheels. Seem to remember over 28 kg is considered fixed unless on wheels, so the electrician must remove covers unless clearly marked only to be removed by gas safe qualified personal to inspect the connections.
As an electrician I don't want to go into a boiler, as a volunteer I do work on boilers, removing covers and cladding for inspections, but these are real boilers, not domestic things, which if they did what they say on the can and boiled the water one would consider faulty.
The problem with being a scheme member is the annual cost, it is not worth being a member unless you are doing regular notifiable work, as well as membership fees, there is cost of meters and books, and the calibration of the meters.
I have my C&G 2391, in fact a degree in electrical engineering, but even so waiting for the railway where I volunteer to accept these are good enough for me to work on electrical equipment, they may ask for 18th Edition, I only have 17th Edition. It is up to their safety officer and their insurers to say OK or not. Even when most of my working life I was employed as an electrician or electrical engineer.