Stop chasing unpaid invoices manually. This workflow does it for you, every morning, with the right tone, at the right time.
An n8n workflow that monitors a Google Sheets tracker and sends escalating reminder emails to clients based on how many days their invoice is overdue. After each email, the tracker is updated automatically.
Reads invoices from your tracker spreadsheet and writes updates back automatically, no separate database needed.
Friendly nudges become firm follow-ups become urgent escalations as days slip by, automatically.
Triggered daily at 9 AM Eastern. You wake up, it's already done. Status changes appear in the sheet.
Each tier checks the current status before sending, so the same client never receives the same email twice.
Three emails, three tones. Tone, color, and urgency shift as the invoice ages — but the format stays consistent so clients recognize the sender. Click a tab to preview each tier.
Hi Lily Jean,
I hope this message finds you well! Just a friendly reminder that Invoice INV-003 for $2000 was due on 2026-02-18 and is currently 7 days past due. I know things can get busy, so I wanted to send a quick nudge in case it slipped past your inbox.
Invoice Details:
| Invoice ID | INV-003 |
| Amount Due | $2000 |
| Original Due Date | 2026-02-18 |
| Days Overdue | 7 |
If payment has already been sent, please disregard this message — and thank you! Otherwise, you can settle the balance whenever it's convenient using the link below:
If you have any questions about the invoice or need anything from me, just let me know and I'll be happy to help. Thanks so much for your continued business!
Best regards,
Kylla Gelaga
Hi Lily Jean,
I hope you're doing well. I wanted to circle back on Invoice INV-003 for $2000, which is now 21 days past due. I sent a reminder a little while ago but haven't heard back yet, so I wanted to make sure it didn't slip through the cracks.
If there's anything on your end — a question about the invoice, a missing detail, or a timing issue — I'd be happy to sort it out together. I'd rather hear about it than leave it unresolved.
Invoice Details:
| Invoice ID | INV-003 |
| Amount Due | $2000 |
| Original Due Date | 2026-02-18 |
| Days Overdue | 21 |
If everything is in order on your side, you can settle the balance using the link below. I'm also open to working out a payment plan if that would help.
Thanks for your time on this — I appreciate it, and I look forward to hearing from you soon.
Best regards,
Kylla Gelaga
Hi Lily Jean,
I'm following up on Invoice INV-003 for $2000, originally due 2026-02-18 — now 82 days past due. I haven't heard back on previous reminders, so I wanted to reach out directly before taking any further steps.
Invoice Details:
| Invoice ID | INV-003 |
| Amount Due | $2000 |
| Original Due Date | 2026-02-18 |
| Days Overdue | 82 |
Could you either settle the balance or let me know what's going on within 5 business days? If there's an issue on your end, I'd rather hear about it and find a workable solution together.
I value our working relationship and want to keep things on professional terms. Hoping we can resolve this soon.
Regards,
Kylla Gelaga
Late invoices steal time, energy, and cash flow. Most freelancers and small teams either forget to follow up, feel awkward doing it, or burn an hour each week on it. This workflow solves all three.
Consistent, on-time reminders measurably shorten payment cycles. Clients pay invoices they're nudged about.
No more sticky notes, calendar pings, or guilty Sundays. The system tracks what you'd otherwise have to remember.
Email tone scales with severity. Clients get warm reminders before firm ones, never an awkward conversation.
You get a personal HTML alert email when an invoice reaches escalation, that's when a phone call matters.
Each morning the workflow walks through the same five-step sequence. No clicks required.
A quick-reference table of when each tier fires and what status it writes back to the Google Sheet.
A warm nudge with the amount, due date, and payment link. Assumes the client simply forgot.
More direct. Acknowledges the prior email, asks about any issues, offers a payment plan.
Serious tone with a 5-business-day deadline. You also get an internal HTML alert email.
Seven simple steps from import to first send.
Create a sheet named Clients Invoicing Tracker with a tab called Invoices. Add the nine required columns including Invoice ID, Client Email, Due Date, and Status.
Set the Due Date column to YYYY-MM-DD so the workflow can correctly calculate days overdue.
In n8n, go to Workflows → Import from file and select Invoice Follow-Up System (1).json.
Link your Google Sheets OAuth2 and Gmail OAuth2 accounts in n8n's credentials settings.
In the Alert Freelancer (30+ Days) node, replace YOUR_EMAIL@example.com with your real address.
All three email templates close with [Your Name]. Swap it for your real name or business name.
Flip the toggle in n8n. The next morning at 9 AM ET, your first batch of reminders goes out.
Planned improvements grouped into three buckets: fixes, new branches, and reporting.