Before an invoice is late: make it easy to pay
The best follow-up is the one you never have to send. A few habits remove most of the friction before the due date:
- Send the invoice to the right person. Ask new customers who handles accounts payable, and whether invoices should go to an AP inbox or portal instead of your day-to-day contact.
- Include what their AP team needs. PO number, their project or job reference, your remit-to details and a W-9 if they haven't got one. A missing PO is one of the most common reasons an invoice sits unapproved.
- Make the terms and due date obvious. "Net 30" means less to a busy AP clerk than "Due November 17".
- Give them a way to pay. A payment link, or clear ACH instructions, removes an excuse to wait.
A simple follow-up schedule
Consistency matters more than the exact days. Pick a schedule, use it for every invoice, and adjust for your terms and for customers you know well. A reasonable starting point for net-30 invoices:
| When | What | Tone |
|---|---|---|
| 3–5 days before due | Friendly heads-up email | Helpful |
| Due date | Optional "due today" note | Light |
| 3–7 days overdue | First overdue reminder | Polite, assumes an oversight |
| ~14 days overdue | Ask for a payment date; offer to send to AP directly | Direct |
| ~21 days overdue | Phone call | Curious: find the blocker |
| ~30 days overdue | Firmer email referencing earlier notes | Firm and factual |
| 45–60 days overdue | Final notice with a clear next step | Formal |
| After that | A decision, not another reminder | — |
Two rules override the calendar: stop the sequence when a customer disputes the invoice, and pause it when they promise a date. More on both below.
Seven email templates you can copy
Keep every message short and self-contained: invoice number, amount, due date, a copy of the invoice and a way to pay, so the reader never has to dig for anything. Replace the bracketed parts and adjust the wording to sound like you.
1. Friendly heads-up 3–5 days before the due date
Subject: Invoice [number] for [amount], due [date]
2. Due today On the due date (optional)
Subject: Invoice [number] is due today
3. First overdue reminder 3–7 days after the due date
Subject: Invoice [number] is now past due
4. Ask for a date About 14 days overdue
Subject: Payment date for invoice [number]?
5. Firmer follow-up About 30 days overdue
Subject: Invoice [number] is 30 days past due
6. Final notice before escalating 45–60 days overdue
Subject: Final reminder: invoice [number], [amount]
Bonus: confirming a promise to pay When a customer gives you a date
Subject: Thanks, noted: invoice [number] on [date]
These templates are general examples, not legal advice. Only mention late fees, interest, holds or other consequences if your contract or invoice terms actually allow them.
When to pick up the phone
Email is efficient, but a short call often finds the real problem in a minute. Call when:
- Two or three emails have gone unanswered.
- The balance is large enough that waiting another week matters to your cash flow.
- A promised payment date has passed.
- You suspect your contact isn't the person who can approve payment.
Go in curious, not combative: "I'm calling about invoice 1042. Is there anything on our side holding it up?" Then confirm whatever you agree by email, using the promise-to-pay template above.
Handling the replies
Sending reminders is the easy part. What you do with the answers is where invoices actually get paid.
- "Can you resend it?" Resend the same day, with the PDF attached and the payment link. Ask if it should go anywhere else too.
- "We need a PO number" / "It's not in our system." Get the PO or the right AP contact, reissue if needed, and restart the clock from there.
- "It's in our next payment run." Ask for the date, confirm it in writing and pause reminders until then.
- A dispute. Stop the reminders. Find out exactly what's disputed, fix or explain it, and only resume once the amount is agreed. Chasing a disputed invoice tells a customer you aren't listening.
- A partial payment or short pay. Find out why before you react. It may be a discount they believe they're owed, a deduction or a mistake. See cash application for more on short pays.
- "We're having cash flow trouble." A realistic payment plan, agreed in writing, is often better than silence. Whether to offer one is a business decision for the owner.
Common mistakes to avoid
- Chasing an invoice that's already paid. Check payments are applied before every reminder. It's the quickest way to annoy a good customer.
- Going silent, then furious. Three months of nothing followed by a stern letter does more damage than steady, polite follow-up.
- Vague messages. "Just checking in on our account" gives the reader nothing to act on. Always name the invoice and amount.
- Empty threats. Don't mention consequences you won't or can't follow through on.
- No record of what was said. Note every reply, promise and dispute against the invoice, so whoever follows up next knows the story.
Use your AR aging report each week to decide who's next on the list.
If you'd rather not do this yourself
This routine works, but only if someone does it every week. That's what Mitt's outsourced AR service is for: reminders like these go out in your name, AI drafts replies to routine questions, our team oversees what goes out and handles escalations, and disputes and decisions come to you.