If your shop’s takings and your rent come out of the same account, you do not have a business account problem. You have a visibility problem, and it costs you twice.
The first cost: you cannot see the business
When everything is in one account, the balance tells you nothing. A good week and a school-fees payment cancel each other out and you end the month roughly where you started, with no idea whether the shop is working.
The second cost: nobody will lend to you
A lender assessing you needs to see money coming in from trade, consistently, over months. A mixed account shows a lender noise. A business account with six months of takings in it is the single strongest thing you can put in front of us when you apply for a working capital loan.
Six months of clean business statements will get you a better rate than any amount of explanation.
The simple version
Open a business account. You need your CAC certificate, your BVN and a valid ID.
Route every sale into it. Give customers that account number only.
Pay yourself a fixed amount into your personal account on the same day each month. That amount is your salary.
Leave the rest. What accumulates is the business’s money, and it earns 12% a year while it sits there.