Using an unregistered electrician
There are many very good electricians who are not part P registered, and could do your work very well, but there are many that won't. You can use an unregistered electrician or do the work yourself, but it will cost you more than a registered electrician to notify your local building control officer. The law is, all notifiable work must be completed by an approved part P installer, or notified to your local building control officer. To find out what is notifyable, please check out notifiable work page.
An unregistered electrician, might not know what they are doing, not complete the work to current electrical & building regulations, not give you an electrical certificate, or at the very least cheat you out of your money. If you do not get a written contract or estimate alarm bells should be ringing, cowboys try not to leave a paper trail so they cannot be found. On completion if you do not receive an electrical certificate, get intouch with either Trading Standards or an Approved part P scheme such as Napit.
All a cowboy wants is to make money without spending any, and are not too fussy how the finished job looks. Most cowboys will tell you anything, just to get your work and your money. The easiest way to stop being cheated is, check them out by asking for identifcation and checking it out. All part P Registered Electricians carry part P Id cards with a registration number, or their company has a membership number. All you have to do is check that Id number with their part P scheme provider such as NAPIT or the NICEIC, ECA, ELECSA, BRE or other.
If you do not get a written quote or estimate with a Company Address & telephone number, you should ask for one. Another thing to ask before the work starts is, ask for proof of public liability insurance cover, if they don't have any you won't be able to claim against them if they do something wrong. By checking them out before the work starts, you are a long way from being cheated.
All part P registered installers are insurance backed, so if for some reason there is a problem, it will be sorted out by the scheme provider. All part P members of every scheme must keep a complaints book, with details of every complaint and how it was dealt with. So the answer is and always will be, only use an electrician who is registered with an approved part P scheme such as NAPIT you will have problems if you don't.
Using a part P Registered Electrician saves you time & money
they have insurance cover and they are regularly assessed
and you know the jobs done right, using one is to your advantage