You may decide to borrow money to finance your building business, either by way of an overdraft or a loan.
Overdraft finance is often very important for building businesses. Funding even a modest project like a home extension can require quite a large sum of money, while employees and subcontractors need paying each week. Stage payments and credit facilities from suppliers can help, but asking for money from customers up front is not generally acceptable. Think about the size of overdraft facility your businesses will need to make sure you don't hit cash flow problems.
You will have to pay interest on any money borrowed and there will also be bank charges due on the operation of your business bank account. Interest and charges are normally debited from your bank account every quarter - your bank will be able to help you estimate the amounts that will be due.
If you accept payment by credit card, you will have to pay monthly credit card charges. Enter these in the cash flow under 'Bank/finance charges and interest'.
Smartphone apps are available to enable trades-people like builders to accept card payments easily when they're out and about.