How to Follow Up on Unpaid Invoices: Email Templates That Work

How to Follow Up on Unpaid Invoices: Email Templates That Work

Following up on unpaid invoices is uncomfortable. Nobody wants to feel like they're begging for money they've already earned. But it has to be done - and how you do it matters.

The right follow-up email is professional, clear, and respectful. It reminds the client without shaming them. It gets results without damaging the relationship. And it escalates appropriately if the client goes silent.

Here are email templates for every stage of the follow-up process, along with guidance on when to use each one.

Before You Follow Up: Set Yourself Up for Success

Before sending any of these emails, make sure your invoice includes a clear due date (not just "Net 30" but the actual calendar date), your contact information, all payment methods and instructions, and an invoice number for easy reference. A complete, professional invoice makes follow-up much simpler.

Template 1: Pre-Due-Date Reminder (3-5 Days Before)

Send this before the due date. It's not a chase - it's a courtesy heads-up.

Subject: Friendly reminder: Invoice #[NUMBER] due [DATE]

Hi [CLIENT NAME],

Just a quick heads-up that Invoice #[NUMBER] for [AMOUNT] is due on [DATE].

You can pay via [PAYMENT METHOD] at [LINK/DETAILS]. Let me know if you have any questions.

Thanks,
[YOUR NAME]

Template 2: Due Date Reminder (On the Due Date)

Send this on the due date itself if you haven't received payment.

Subject: Invoice #[NUMBER] due today

Hi [CLIENT NAME],

Invoice #[NUMBER] for [AMOUNT] is due today, [DATE].

If you've already sent payment, please disregard this email. If not, you can pay via [PAYMENT METHOD] at [LINK/DETAILS].

Thanks for your prompt attention,
[YOUR NAME]

Template 3: First Follow-Up (5-7 Days Overdue)

Keep this casual and assume the invoice just got lost or forgotten. Most late payments at this stage aren't intentional.

Subject: Checking in on Invoice #[NUMBER]

Hi [CLIENT NAME],

I wanted to check in on Invoice #[NUMBER] for [AMOUNT], which was due on [DATE]. I haven't seen payment come through yet - just wanted to make sure the invoice didn't get lost in the shuffle.

You can pay via [PAYMENT METHOD] at [LINK/DETAILS]. Let me know if you need a copy of the invoice or have any questions.

Thanks,
[YOUR NAME]

Template 4: Second Follow-Up (14 Days Overdue)

Your tone shifts slightly here - still professional and respectful, but a bit more direct.

Subject: Invoice #[NUMBER] - 14 days past due

Hi [CLIENT NAME],

Invoice #[NUMBER] for [AMOUNT] is now 14 days past its due date of [DATE]. I'd appreciate payment as soon as possible.

If there's an issue with the invoice or a reason payment has been delayed, please let me know so we can work it out. Otherwise, payment can be made via [PAYMENT METHOD] at [LINK/DETAILS].

Thank you,
[YOUR NAME]

Template 5: Third Follow-Up (30 Days Overdue)

At this point, you're firmer. Consider whether late fees apply per your contract.

Subject: Final reminder: Invoice #[NUMBER] - 30 days overdue

Hi [CLIENT NAME],

Invoice #[NUMBER] for [AMOUNT] is now 30 days past due. I've sent several reminders and haven't received payment or a response explaining the delay.

[IF LATE FEES APPLY: Per our agreement, a late fee of [AMOUNT] has been added, bringing the total due to [NEW TOTAL].]

Please arrange payment by [DATE] to avoid further action. If you're experiencing financial difficulty, please contact me directly - I'm open to discussing a payment arrangement.

Payment can be made at [LINK/DETAILS].

Regards,
[YOUR NAME]

Template 6: Phone Call Script (30+ Days Overdue)

Sometimes email stops working. Pick up the phone.

"Hi [CLIENT NAME], this is [YOUR NAME]. I'm calling about Invoice #[NUMBER] for [AMOUNT]. It's now [X] days past due, and I wanted to check in directly. Is there anything I can help resolve on your end, or can I expect payment this week?"

Keep it calm and professional. You're a business owner following up on a legitimate debt. Don't apologize for calling.

Template 7: Final Notice Before Collections (60 Days Overdue)

This is your last email before escalating to a collections agency or small claims court.

Subject: Final notice: Invoice #[NUMBER] - [AMOUNT] past due

Dear [CLIENT NAME],

Despite multiple attempts to contact you, Invoice #[NUMBER] for [AMOUNT] (due [DATE]) remains unpaid. This is a final notice before I refer this account to a collections agency [or take legal action].

To resolve this matter, please remit payment in full by [DATE] via [PAYMENT METHOD] at [LINK/DETAILS].

If I do not receive payment or hear from you by that date, I will proceed accordingly.

Regards,
[YOUR NAME]

Tips for All Follow-Up Emails

Reference the invoice number every time. Makes it easy for the client (and their accounting team) to locate the invoice.

Always include the payment link or instructions. Remove every possible barrier between "I need to pay this" and "payment sent."

Keep a paper trail. All correspondence in writing. If this goes to collections or small claims, you'll want documentation.

Automate the early reminders. Pre-due and first follow-up reminders are easy to automate with WaffleInvoice. You set it up once per client and the software sends reminders automatically - so the first email isn't you, it's just a system notification, which is emotionally easier.

Create a free WaffleInvoice account to automate payment reminders and stop chasing invoices manually.

Related reads: How to Follow Up on Late Payments · How to Handle Clients Who Don't Pay · Payment Terms for Freelancers