What is the difference between a past due vs outstanding invoice?
In past due vs outstanding invoice terms, an outstanding invoice is any invoice not yet paid, whether or not it is due; a past due invoice is still outstanding after its due date. A customer who received the goods or services generally still owes a late invoice, plus any late fees the contract allows.
Past due vs outstanding invoice: an example
An invoice dated March 1 with net-30 terms is outstanding from March 1 and becomes past due on March 31 if unpaid.
Do I have to pay a late invoice if I’m the customer?
Generally yes, if you agreed to the purchase and received what you ordered. If the invoice is wrong or the work was defective, dispute it promptly in writing.
Related answers
When to send an invoice to collections · Client stopped responding
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Frequently asked questions
When does a past due invoice go to collections?
Often around 60 to 90 days past due; see our timing guide.
About Small Biz Debt Collection
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Sources: Commercial Law League of America, “Probability of Recovering Commercial Debt with Age” (accessed Oct 18, 2026).
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