Make the result useful
vendor-invoice aging
This worksheet makes vendor-invoice aging explicit from the exact figures you enter. Review the period and basis of every amount before comparing results.
Use a conservative scenario as well as the base scenario; the calculation describes assumptions rather than predicting behavior.
The assumptions that move this result
Invoice
Original billed amount.
Payments
Payments applied to this invoice.
Days
Days since invoice date.
invoice − payments; paired with invoice age in days
Read the result as a planning measure for the selected period.
Read the number in context
Worked scenario
$1,450 − $400 leaves $1,050 open at 38 days.
Edge case
A disputed invoice can age without being payable.
It does not determine due dates or collections action.
Before you act
• Confirm every input uses the same time period.
• Test a downside scenario before relying on the result.
• Keep source records with the decision.
Formula
invoice − payments; paired with invoice age in days
What period should I use?
Use one consistent reporting or planning period for every input.
Does this predict performance?
No. It only performs the stated arithmetic.
Can it replace records or advice?
No. Confirm decisions with source records and appropriate professional guidance.