When a company obtains a utility bill but will not pay it right away, it should debit utilities expense and credit accounts payable.
The accounting equation, Assets = Liabilities + Owners Equity means that the total assets of the business are all the time equal to the total liabilities plus the total equity of the business. This is true at any time and applies to each matter.
In this case the balance sheet or accounts payable have an increased of $500, and the income statement has a utilities expense of $500. The expense decreases the net income, retained earnings, and therefore owners’ equity in the business.