self-employment mandatory paper work

Hi all,
I have completed 12 months of my job. I earned as a self-employment 6400 pounds and 27000 from my employment.
I have original accountant letter head and Original accounts details transcation.
Is it mandatory that I have to work for some LIMITED company in my self-employment period?
3000 pounds I work for sole trader. Is it accpetable in the Home office requirement?
Is INVOICE a mandatory requirement with the company address?

Awaiting for prompt reply.
Kind regards
Farhan khan

refer to guidance notes. sor self employemnt you have to show invoice explanations and accountant letter they are must.

no u can be sole trader or operate by ltd compnay. in your case you are in self employed capacity.