When you're first starting out, you should still keep separate bank accounts for business and personal, but it's true that it is more important to pay the rent or fix a busted pipe even if you have to do an unplanned owner's draw from the business account to do it. That's one of the reasons the IRS has sole proprietors file business and personal taxes on the same form. It is understood that such a young business is fluid between business money and life expenses money. But as you grow it becomes more important to keep everything separate all the time. As soon as you get that first employee, you need to protect the business money for the business only or you could get into big problems.