UIF registration if sole proprietor

[Dave A]

or as a business, in which case I have to supply business registration papers, which I obviously don't have. What do I register them under?

Back in the day when I was a sole proprietor, I just used my ID number to fill in any "company registration number" fields, and my "company registration papers" was a copy of my ID book and a "this is to confirm details of sole proprietorship" letter on a business letterhead.