Short answer: An overdue invoice email should state the invoice number, the amount, how many days past due it is, and one specific action with a date. Send a short reminder a few days before the due date, another on the due date, then follow up at 7, 14, and 30 days past due, with the tone firming each time. Keep it factual, never apologetic, and always attach the invoice again.
Last updated: July 2026.
Most late invoices are not disputes. They are invoices that got lost in an inbox, went to the wrong person, or are sitting in an approval queue nobody is watching. That is good news, because it means the fix is usually a clear email sent to the right person at the right time, not a lawyer.
The mistake companies make is treating the reminder like an apology. They write "just checking in" and "sorry to bother you," bury the amount in a paragraph, and give the reader nothing to do. The invoice stays unpaid, and the sender feels rude for having asked. This guide gives you the sequence, the wording, and the templates that work instead.
What is a past due invoice?
A past due invoice is an invoice that has not been paid by the due date set in its payment terms. If you bill on net 30 payment terms and the invoice is dated July 1, it is due July 31. On August 1 it is past due by one day, and the clock that matters to your cash flow starts running.
Past due is not the same as in dispute. A disputed invoice is one the customer has told you they will not pay as issued, usually because of a pricing error, a missing purchase order, or work they say was not delivered. Disputes need a conversation and a corrected invoice. Everything else needs a reminder.
The payment reminder sequence that actually collects
One email is not a collections process. What works is a short ladder of messages with a rising temperature, scheduled in advance so nobody has to decide each time whether it feels awkward to chase.
| When | Tone | What the email does |
|---|---|---|
| 3 to 5 days before due | Neutral, helpful | Confirms the invoice arrived and is scheduled for payment. Catches the ones that never reached accounts payable. |
| Due date | Neutral | Notes the invoice is due today and repeats the payment link or bank details. |
| 7 days past due | Direct | States the invoice is past due and asks for a payment date, not a vague promise. |
| 14 days past due | Firm | Escalates to a named person and asks whether anything is blocking approval. |
| 30 days past due | Firm, formal | References the agreed terms, applies any late fee, and sets a deadline. |
| 45 to 60 days past due | Final | Final notice before you pause work or hand the account to collections. |
Two details make this ladder work. First, send from a person, not from a no-reply billing address, because a reply is what you actually want. Second, copy the right people as you climb: the day-7 email goes to your contact, the day-14 email adds accounts payable, and the day-30 email adds the person who signed the agreement.
How do I write an overdue invoice email?
Lead with the facts, then the ask. A good overdue invoice email names the invoice number and amount in the first sentence, says exactly how many days past due it is, gives one clear action, and sets a date for that action. Keep it under 120 words, attach the invoice again, and repeat the payment method. Do not apologize for asking, and do not threaten anything you are not prepared to do.
The five rules that separate a reminder that gets paid from one that gets archived:
- Put the number in the subject line. "Invoice 1042, 5,400 dollars, 14 days past due" gets opened. "Following up" does not.
- Ask for a payment date, not a payment. "When will this be paid?" is easy to ignore. "Can you confirm the date this will be released?" needs an answer.
- Attach the invoice every time. Removing the excuse of "I cannot find it" ends a surprising share of delays.
- Name the blocker. Ask directly whether it is waiting on approval, a purchase order number, or a missing vendor form.
- Keep the record. Log every reminder against the invoice so the next person to touch it can see the history.
Overdue invoice email subject lines
| Stage | Subject line |
|---|---|
| Before due | Invoice 1042 due July 31, confirming it reached you |
| Due today | Invoice 1042 (5,400 dollars) is due today |
| 7 days past due | Invoice 1042, 7 days past due, payment date needed |
| 14 days past due | Past due: invoice 1042, 5,400 dollars, what is blocking approval? |
| 30 days past due | Invoice 1042 is 30 days past due, late fee now applies |
| Final notice | Final notice before collections: invoice 1042, 5,400 dollars |
Past due invoice email templates
Adapt these, do not paste them. The details (invoice number, amount, date, contact) are what make a reminder feel like a real person tracking a real balance rather than an automated nag.
1. Before the due date
Subject: Invoice 1042 due July 31, confirming it reached you
Hi Dana, invoice 1042 for 5,400 dollars is due on July 31. I am just confirming it made it to the right place and is scheduled. If it needs a purchase order number or a different email address to get through approval, tell me and I will resend it today. Invoice attached again for convenience.
2. On the due date
Subject: Invoice 1042 (5,400 dollars) is due today
Hi Dana, invoice 1042 for 5,400 dollars is due today, July 31. You can pay by card or ACH using the link on the invoice, which is attached. If payment is already in progress, let me know the date it will land and I will note the account.
3. Seven days past due
Subject: Invoice 1042, 7 days past due, payment date needed
Hi Dana, invoice 1042 for 5,400 dollars was due on July 31 and is now 7 days past due. Can you confirm the date the payment will be released? If it is stuck in approval or waiting on paperwork from us, say the word and I will clear it today.
4. Fourteen days past due, escalating
Subject: Past due: invoice 1042, 5,400 dollars, what is blocking approval?
Hi Dana, invoice 1042 for 5,400 dollars is now 14 days past due. I have copied your accounts payable team so nothing is waiting on a single inbox. Our terms are net 30, so I need either a payment date or the specific blocker. If there is an issue with the invoice itself, tell me what is wrong and I will reissue it.
5. Thirty days past due, with late fee
Subject: Invoice 1042 is 30 days past due, late fee now applies
Hi Dana, invoice 1042 for 5,400 dollars is 30 days past due. Under section 4 of our agreement, a late fee of 1.5 percent per month now applies, which adds 81 dollars. The revised balance is 5,481 dollars. Please arrange payment by August 20. If there is a reason this cannot be paid, I would rather hear it than keep sending reminders.
6. A strong letter for an outstanding payment
Subject: Formal notice: invoice 1042, 5,481 dollars outstanding
Dana, this is a formal notice that invoice 1042, dated July 1 and due July 31, remains unpaid at 5,481 dollars including late fees. The work it covers was delivered and accepted on June 28. We have sent reminders on July 28, July 31, August 7, August 14, and August 30 without a payment date. Please remit the full balance by September 10. If we do not receive payment or a written payment plan by that date, we will pause active work and refer the balance for collection.
7. Final notice before collections
Subject: Final notice before collections: invoice 1042, 5,481 dollars
Dana, invoice 1042 is now 60 days past due at 5,481 dollars. This is the final notice before the account is referred to a collections agency, which we would rather avoid for both of us. Payment or a signed payment plan is due by September 10. If the balance is disputed, reply today with the specific line you are disputing and we will hold the referral while we resolve it.
What do you say in a payment reminder email?
Say what is owed, since when, and what you want the reader to do next. A payment reminder needs four things: the invoice number and amount, the original due date and days past due, a single clear request (a payment date), and the payment method repeated. Everything else is padding. Friendly is fine, vague is not, and the reader should never have to open an attachment to learn what you want.
Can I charge a late fee on an overdue invoice?
Generally you can charge a late fee only if the customer agreed to it before the work, in the contract or in the payment terms printed on the invoice. A fee that appears for the first time on a reminder email is hard to enforce and tends to start an argument you did not need. Common practice in US business billing is 1 to 1.5 percent per month on the outstanding balance, and state law can cap the interest rate you are allowed to charge, so set the rate once, put it in your agreement, and apply it consistently rather than as a punishment for customers you are annoyed with. This is general information rather than legal advice.
The fee is not really about the money. It is about making late payment cost something, so your invoice stops being the one that gets pushed to next month.
How long should you wait before sending a past due invoice reminder?
Do not wait at all. Send the first follow-up the day after the due date, when the balance is one day late. Waiting two weeks teaches the customer that your due date is a suggestion, and it puts you at the back of the queue behind vendors who chased on day one. The early reminder also catches the most common cause of lateness, which is an invoice that never reached the person who approves payments.
When to stop emailing and pick up the phone
Around the 14 day mark, if you have sent two reminders and heard nothing, email has failed and repeating it will not help. Call your contact, and if they do not answer, call accounts payable directly. A two minute call surfaces the real reason (the invoice was rejected for a missing purchase order number, the approver left the company, the payment run is monthly and you missed it) far faster than a fifth email. Then send a short written summary of what you agreed on the call, because that is the record that matters later.
Overdue invoice emails versus dunning emails
These two get confused constantly, and they are different jobs.
| Overdue invoice email | Dunning email | |
|---|---|---|
| Trigger | An invoice passed its due date and was not paid | A card or ACH payment failed, usually on a subscription |
| Typical customer | B2B, paying on terms after approval | Any customer on an automatic charge |
| The problem | The payment was never initiated | The payment was attempted and declined |
| The fix | Get a human to approve and release payment | Get the customer to update a payment method |
If your revenue is recurring and the failure is a declined card, you want a retry schedule and a proper dunning email sequence instead. If the customer is a business paying an invoice on terms, you want the ladder above.
Track whether your reminders are working
Chasing feels productive, so it is worth checking whether it is. Three numbers tell you the truth. Your days sales outstanding should trend down as the sequence takes hold. The share of your balance sitting past 60 days on the accounts receivable aging report should shrink, because that is the money most likely to become bad debt. And the response rate to the day-7 email tells you whether you are emailing the right person at all.
If you are sending these by hand across dozens of open invoices, the sequence is the first thing to automate. Tools that chase every open invoice automatically by email and SMS until it is paid free your team to work the handful of accounts that genuinely need a phone call, which is where the recoverable money actually is.
Where reminders fit in the wider process
Reminder emails are the last mile of a system that starts long before an invoice goes late. Clear terms agreed up front, an invoice that is correct on the first send, and a tidy accounts receivable process prevent most of the chasing. When invoices are wrong or confusing, customers use that as a reason to delay, which is why the billing experience and your collection rate are the same problem wearing different hats. Get the invoicing process right and the reminder ladder has far less work to do.