The definition of accounts payable is short: amounts a business owes suppliers for goods and services received but not yet paid for, carried as a current liability. The difficulty is never the definition itself but the boundary between it and three neighbouring terms it gets confused with. Accruals, notes payable and accounts receivable each sit next to payables and each is a different thing, and the confusion has practical consequences at a period end because the wrong classification puts a cost in the wrong place. This page is the definition, and the three boundaries drawn clearly.
The definition, and the timing inside it
Received, not yet paid. The word received is doing the work: the liability arises when goods or services are received, not when the invoice arrives and not when it is paid. That is why a cut-off exists and why unrecorded liabilities are what auditors look for.
Not accruals, though they are cousins
An accrual is an estimate of what has been received and not yet invoiced. Payables is what has been invoiced and not paid. Both belong in the period; they are recorded differently because one is known and the other estimated, and they are often shown together on a balance sheet.
Not notes payable, and not receivable
Notes payable are formal borrowings with terms and usually interest, which is a financing liability rather than a trading one. Accounts receivable is the mirror image: what customers owe you. Those two confusions are common and consequential in different ways.
Questions people ask about definition accounts payable
Is accounts payable short term?
Normally yes, settled within a year and shown as a current liability. Anything with longer terms is worth discussing with your accountants, because the classification may differ.
Does it include disputed invoices?
Generally yes, since the obligation exists, though a genuinely disputed amount may be treated differently. That judgement belongs with your own advisers.
Where do I see it?
As a line on the balance sheet, supported by an aging report that splits it by how overdue it is. On the worked example on this site, $48,000 current, $21,000 at thirty days, $9,500 at sixty and $4,200 beyond is $82,700 owed, 42% of it overdue, with days payable outstanding of 30.26.