Becoming a member of a CPS. do i have to?

Hi, I am currently a practicing full time employed maintenance electrician, and a member of the IET. I have started my own limited company now, doing work on the side outside of my main job. I am looking to do work in industrial, commercial and domestic properties. I have completed a full electrical apprenticeship, electrical HNC, C&G 2382-22 (18th ed) and 2391- 52 (initial and periodic insp+test) and more. I am also in the middle of applying for an ECS gold card which I should have no issues obtaining.

I am struggling to understand the way of which I can go about doing electrical work as a self-employed person. Id like to be able to do minor works, CU/DB replacements, EICR’s etc. To my understanding, you have to be part of a CPS (Napit. Niceic etc…) but some electricians have told me otherwise and said that you don’t need to be part of a CPS in order to be able to do this work.

I don't want to find myself on the wrong side of the law and i do pride myself in carrying out great quality work.

The issue I have is that the CPS’s don’t recognise my apprenticeship (EAL level 3 NVQ extended diploma in engineering maintenance (electrical)) (600/2084/2), and want me to do the experienced workers assessment, which I don’t want to do as In my opinion I am already more than highly qualified and experienced enough to be able to do all of this work.

Is there any ways around this problem I am experiencing? I am also seeing tons of conflicting opinions online.

i know you can do the method of paying local building control to check and sign off any work you've done, but i asked them and they said £270 a time!!!! which would make it pointless in me doing bits on the side

bottom line: do I HAVE to be part of a CPS to legally carry out minor works, DB replacements, EICRs. And if the answer is NO, then what are the benefits to being part of a CPS?? And does anyone know a way i can join a CPS with my current qualifications. 

thank you for your time!