Go to Reports → All Reports and choose Payables aging under Financial statements.
Set the date range.
Each row is a vendor. The columns run from Not due yet through 0–30 days, 31–60 days and so on, up to Over 360 days.
Click Export to download it.
Tips
Pay overdue bills first to protect supplier relationships and avoid late fees.
For more detail, see Expenses by vendor and Expenses by account under All Reports.
Bill shows as owed but you've paid it? Record the payment under Manage payments.