Past Due Invoice Letter: Free Templates for Late Payments
Quick Answer
A past due invoice letter reminds a customer that an invoice is unpaid after its due date. Include the invoice number, original amount, due date, amount now owed, how to pay and who to contact. Start with a friendly reminder a few days after the due date, follow with firmer notices at set intervals and finish with a final notice that states the next step. Charge late fees only if your contract or invoice terms allow them and your state permits them.
Late payments are one of the biggest cash flow problems for small businesses. You did the work, sent the invoice and the due date came and went. Most late payers aren't trying to avoid paying; the invoice got lost, the person who approves payments was out or it simply slipped through. A clear, polite follow-up process gets most invoices paid without damaging the relationship.
This guide includes free past due invoice letter templates, from a friendly first reminder to a final notice, plus phone scripts, guidance on late fees and payment plans and tips for preventing late payments.
Note: This is general information, not legal advice. Collection practices, late fees and interest are governed by contracts and state law. Talk to an attorney before taking legal action or charging fees not in your terms.
What to Include in a Past Due Letter
| Element | Why it matters |
|---|---|
| Invoice number and date | Helps the customer find it |
| Original amount and due date | Shows what was owed and when |
| Days past due | Makes the timeline clear |
| Amount now owed | Including any late fees allowed by your terms |
| How to pay | Payment link, address, accepted methods |
| Copy of the invoice | Saves the customer from searching |
| Contact person | Who to call with questions or disputes |
| Next step and date | What happens if it stays unpaid (later notices) |
A Simple Follow-Up Schedule
| When | Action | Tone |
|---|---|---|
| 3 days before due | Courtesy reminder (optional) | Friendly |
| 1–3 days past due | First reminder | Friendly |
| 14 days past due | Second notice and a phone call | Polite but direct |
| 30 days past due | Third notice; consider pausing work | Firm |
| 45–60 days past due | Final notice with next steps | Firm and clear |
| After final notice | Collection agency, small claims or attorney | As advised |
Adjust the timeline to your payment terms and industry. Put the schedule in writing so every invoice is followed up the same way.
Template 1: Friendly First Reminder
Subject: Friendly reminder: Invoice #[number] was due [date]
Hi [Name],
I hope all is well. This is a quick reminder that invoice #[number] for $[amount], dated [date], was due on [due date]. I've attached a copy for your convenience.
You can pay [online at link / by check to address / by ACH]. If payment is already on its way, thank you, and please disregard this note.
Please let me know if you have any questions.
Thanks,
[Your name]
[Business name] | [Phone]
Template 2: Second Notice
Subject: Second notice: Invoice #[number] is [14] days past due
Hi [Name],
Our records show that invoice #[number] for $[amount], due on [due date], is now [14] days past due. A copy is attached.
Please arrange payment by [date] using [payment methods]. If there's a problem with the invoice or you need to discuss timing, please call me at [phone] so we can work it out.
Thank you,
[Your name]
Template 3: Third Notice
Subject: Invoice #[number] is 30 days past due
Dear [Name],
Invoice #[number] for $[amount] is now 30 days past due. We've sent reminders on [dates] and haven't received payment or a response.
[If allowed by your terms: Under our terms, a late fee of [amount/rate] has been added, bringing the balance to $[total].]
Please pay the balance by [date]. [If applicable: Until the account is current, we will need to pause new work / place new orders on hold.]
If you're having difficulty paying, please contact me at [phone] to discuss a payment plan.
Sincerely,
[Your name]
[Title]
Template 4: Final Notice
Subject: Final notice: Invoice #[number]
Dear [Name],
This is a final notice that invoice #[number], originally due on [due date], remains unpaid. The balance is $[amount].
Despite our reminders on [dates], we have not received payment or a response. If we do not receive payment or hear from you by [date], we will [refer the account to a collection agency / pursue other options available to us].
We would prefer to resolve this directly. Please pay at [link/address] or call me at [phone] to discuss.
Sincerely,
[Your name]
[Title]
Only state a next step you're actually prepared to take. Empty threats damage credibility and can create legal problems.
Template 5: Payment Plan Agreement
Subject: Payment plan for invoice #[number]
Hi [Name],
Thank you for talking with me about invoice #[number]. As agreed, the balance of $[amount] will be paid as follows:
• $[amount] by [date]
• $[amount] by [date]
• $[amount] by [date]
If a payment is missed, the full remaining balance will be due immediately. Please reply to confirm this plan.
Thank you,
[Your name]
Phone Scripts
First Call
"Hi [Name], this is [your name] from [business]. I'm calling about invoice #[number] for $[amount], which was due on [date]. I wanted to check whether you received it and if there's anything I can help with to get it processed."
When the Customer Says It's Coming
"Great, thank you. When should I expect it, and by which method? I'll make a note and send you a quick email confirming."
When the Customer Disputes the Invoice
"I appreciate you telling me. Can you walk me through what doesn't look right? I'll review it today and get back to you by [time]. Is the rest of the invoice OK to pay in the meantime?"
Write down what was said on every call, with the date and the person you spoke to.
Late Fees and Interest
Late fees can encourage on-time payment, but only if they're set up correctly:
- State the late fee or interest rate in your contract, quote or invoice terms before work begins.
- Check your state's rules on late fees and maximum interest rates.
- Apply fees consistently.
- Show the fee as a separate line on the past due notice.
- Consider waiving a fee for a long-time customer who pays promptly once reminded.
When to Pause Work
For ongoing services or projects, many businesses pause new work when an account is significantly past due. If your contract allows it, tell the customer in writing before pausing, explain what's needed to resume and keep track of the date. Pausing work is often more effective than repeated reminders.
What the FDCPA Covers
The federal Fair Debt Collection Practices Act defines a "debt collector" mainly as someone who regularly collects debts owed to another, or whose business is mainly collecting debts. It defines "debt" as an obligation of a consumer arising from a transaction primarily for personal, family or household purposes. The definition also includes creditors who, when collecting their own debts, use a name other than their own that suggests a third party is collecting.
In practice, if you collect your own invoices under your own business name, the FDCPA's debt collector rules may not apply to you, but state collection laws might, especially for consumer customers. Never use a fake collection agency name, and be honest, polite and professional in every collection message. If you hire a collection agency, it may be covered by these rules. Ask an attorney about your situation.
Collection Options After the Final Notice
| Option | When it fits | Considerations |
|---|---|---|
| Keep negotiating | Customer is responsive | Payment plan or partial settlement |
| Collection agency | Customer won't respond | Agencies usually keep a percentage of what they collect |
| Small claims court | Smaller amounts within your state's limit | Filing fees and time; rules vary by state |
| Attorney | Larger amounts or contract disputes | Demand letter or lawsuit |
| Write it off | Cost of collecting exceeds the amount | Ask your accountant about bad debt |
Contractors may also have lien rights for unpaid work. Lien deadlines are strict and vary by state, so talk to an attorney early.
Preventing Late Payments
- Clear terms up front: due date, accepted methods, late fees.
- Invoice promptly when work is complete.
- Make invoices clear and easy to pay. See how to make your invoices look professional.
- Offer online payment and several payment methods.
- Take deposits for larger jobs.
- Use progress billing on long projects. See project billing.
- Send reminders before the due date.
- Know who approves payments at each customer.
Tracking Past Due Invoices
| Customer | Invoice # | Amount | Due date | Days late | Last contact | Next step | Status |
|---|---|---|---|---|---|---|---|
Review this list every week. An accounts receivable aging report, grouped by 0–30, 31–60, 61–90 and 90+ days, shows where cash is stuck.
Example: A Small Marketing Agency
A marketing agency had more than a quarter of its invoices paid late, and the owner spent hours each month chasing them. She added clear terms and a late fee to every proposal, switched to invoices with an online payment link and set up a reminder schedule: a friendly email at three days, a call at 14 days and a pause on new work at 30 days. Within two months, most clients paid within terms, and the few late ones paid after the first reminder.
Common Past Due Mistakes
- Waiting too long to send the first reminder.
- Angry or emotional messages.
- Missing invoice details in the reminder.
- Late fees not in your terms.
- Threats you won't carry out.
- No record of calls and emails.
- Continuing work for customers months behind.
Past Due Invoice Checklist
| Step | Done? |
|---|---|
| Set clear payment terms before work starts | |
| Invoice promptly with easy payment options | |
| Send a friendly reminder within a few days of the due date | |
| Follow up by phone at about two weeks | |
| Send firmer notices on a set schedule | |
| Offer a payment plan when appropriate | |
| Send a final notice with a real next step | |
| Document every contact |
Template 6: Text Message Reminder
"Hi [Name], this is [your name] from [Business]. Just a quick reminder that invoice #[number] for $[amount] was due [date]. You can pay here: [link]. Thanks!"
Text reminders work well for small service businesses whose customers prefer texts. Get the customer's permission to text, keep the message short and never include sensitive account details.
Template 7: Reminder Before the Due Date
Subject: Upcoming: Invoice #[number] due [date]
Hi [Name],
A quick heads-up that invoice #[number] for $[amount] is due on [date]. You can pay anytime at [link]. Thank you for your business!
[Your name]
A courtesy reminder a few days before the due date prevents many late payments altogether.
Handling Invoice Disputes
- Listen and write down exactly what the customer disputes.
- Review the contract, quote, change orders and job records.
- Respond in writing with what you found.
- Correct real errors quickly with a revised invoice.
- Ask the customer to pay any undisputed portion now.
- Escalate to the owner if you can't resolve it.
Many late payments are really disputes. Settling the disputed part quickly often unlocks payment for the rest.
Who Should Handle Collections?
In a small business, collections often fall to the owner, which can feel awkward when you also manage the relationship. Some businesses assign reminders to a bookkeeper or office manager, so the owner stays focused on the work and the customer. Whoever handles it should have the authority to set up payment plans within limits you set.
B2B vs. Consumer Customers
| Business customers | Consumer customers | |
|---|---|---|
| Who to contact | Accounts payable and your project contact | The customer directly |
| Common delays | Approval processes, missing PO numbers | Cash flow, forgotten bills |
| What helps | Including PO numbers, sending to the right AP email | Online payment links, text reminders |
| Rules | Mainly your contract | Contract plus state consumer collection rules |
For business customers, ask during setup who receives invoices and whether they need a purchase order number on every invoice. Missing PO numbers are a common reason invoices sit unpaid.
Past Due Letter Quick Tips
- Start friendly; most late payers just forgot.
- Always attach the invoice.
- Make paying easy with a link.
- Call before the account gets far behind.
- Write down every contact.
- Only state next steps you'll take.
Cash Flow While You Wait
Late payments hurt most when cash is tight. Keep a simple cash flow forecast that shows when you expect each invoice to be paid, and plan payroll and supplier payments around realistic dates, not invoice due dates. See how to create a cash flow planner.
Setting Payment Terms That Get Paid
| Term | Example |
|---|---|
| Due date | Due on receipt, Net 15 or Net 30 |
| Accepted methods | Card, ACH, check |
| Deposit | 50% before work begins on jobs over a set amount |
| Late fee | As allowed by law and stated in your terms |
| Pause policy | Work paused on accounts 30+ days past due |
Shorter terms and deposits reduce how much money is at risk at any time.
Thank Customers Who Pay
When a late invoice gets paid, send a quick thank-you. It keeps the relationship positive and makes the next reminder easier. A short "Payment received, thank you!" is enough.
Over time, note which customers pay on time and which always need reminders. That history can guide deposits and terms for future work.
Get Paid Faster With Updoot
Updoot's invoice generator creates clear, professional invoices with your terms, so customers know exactly what they owe and when. See also the hourly contractor invoice template.