Hallo everyone,my name is Conrad

I was hoping someone can shed some light on some questions that I have regarding starting up my own business/self employed.
I have been working in the electrical industry for about 4 years now and are planning to start up my own electrical business on the side.I have done my C&G2330 Electrical Installation Levels 2&3, 17th Edition and C&G2391 Testing and Inspection courses.
Most of my installation/repair work will be in domestic dwellings.With the qualifications that I have,am I allowed to do installations,do I have to be registered with a body etc.What is the procedure?

This self employment is quite new to me and want to follow everything to the letter before I start up.
Can anyone give me advice on this topic,it will be much appreciated.

Regards