When is an invoice officially past due?
The day after the due date on the invoice. Net 30 means the customer has 30 days from the invoice date; on day 31 the invoice is past due, and you can say so plainly. If the invoice carried no due date, the terms you agreed elsewhere apply — and if nothing was agreed anywhere, that's the real problem to fix on the next invoice, not something a reminder can repair.
_Past due_ and _overdue_ mean the same thing. Use whichever you like; your customer's accounts system will understand both.
Before you send anything: check three things
- Did the invoice arrive? Wrong email address, a spam filter, an accounts inbox nobody reads — delivery failure explains more "late" payments than bad faith does.
- Is anything on it disputed? If the customer has questioned a line, chasing the total makes it worse. Resolve the line first.
- Did they part-pay? A partial payment changes the number you're chasing and usually signals intent to pay the rest. Chase the balance, and say you noticed the payment.
The reminder sequence: day 1, day 15, day 30
Day 1 past due — the nudge. One or two sentences, warm, zero accusation: _"Just a reminder that invoice #214 for $860 was due yesterday — here's a copy in case it got buried. Anything you need from me?"_ Attach the invoice. Most invoices die here, quietly and politely.
Day 15 — the direct ask. Still polite, now specific: restate the amount, the original due date, and how to pay. Ask a question that requires an answer: _"Can you let me know when this is scheduled for payment?"_ A question converts silence into either a date or a reason — both are progress.
Day 30 — the consequence note. State, without heat, what happens next: work pauses, late fees apply if they were agreed on the invoice, or the debt goes to a formal process. Never threaten anything you haven't already put in writing on the invoice itself — a late fee that appears for the first time in a chase email is a new demand, not a term.
The pattern underneath all three: short, factual, and always carrying the invoice with it. The reminder's job is to make paying easy, not to make the customer feel bad.
What makes reminders awkward — and what fixes it
Nobody enjoys writing these. The awkwardness comes from improvising: each chase email is written one-off, in whatever mood the day supplied, to a customer you'd like to keep. A fixed sequence removes the improvisation — the words were decided on a calm day, the timing is a rule rather than a judgment call, and the customer experiences consistency instead of escalating tension. The chase stops being personal, which is precisely what keeps the relationship intact.
When to stop chasing
A reminder sequence needs an exit, and there are four:
And one stop that's a business decision, not a rule: at some point — 60, 90 days — the question stops being "how do I word the next email" and becomes "is this debt worth formal recovery, and is this customer worth keeping." No reminder sequence answers that; it just makes sure you arrive at the question with a clean record of having asked properly.
- They paid. Stop everything, including the reminder already scheduled. A chase that lands after payment reads as carelessness and undoes the goodwill of the whole exchange.
- They disputed it. Pause the sequence and deal with the dispute. Chasing a disputed invoice hardens the dispute.
- They replied with a date. Hold until the date passes. If it passes unpaid, resume — referencing their own promise, which is the strongest card you hold.
- The email bounced. Stop sending and find a human channel. Reminders into a dead mailbox only build a false paper trail.