I've been running my own very tiny business for 3 year but I just use my own personal account (I know I'm crap). but my turnover is tiny -less than £2,000 per year and no profit yet . . .
However, in a couple of months I am doing a large show which I will probably have to hire a Card terminal thingy as takings will hopefully be much larger. I'm guessing I will have to have a business account.