Chasing unpaid invoices is one of the worst parts of running a small business. It's awkward, it's time-consuming, and it directly impacts your cash flow. The average small business has $84,000 in unpaid invoices at any given time. That's not a stat. It's a crisis.
Here's the thing: most late payments aren't because clients don't want to pay. They forgot, they lost the email, or it fell to the bottom of their to-do list. A consistent, professional follow-up sequence solves this. And when it's automated, you never have to think about it again.
Let me show you exactly how to set this up.
The Follow-Up Sequence That Actually Works
After testing different approaches with dozens of small business clients, here's the sequence that consistently gets the best results:
- Day 0: Invoice sent (with clear payment terms and a direct payment link)
- Day 3: Friendly reminder ("Just making sure this didn't get buried in your inbox")
- Day 7: Firmer follow-up ("Your invoice is now 7 days past due")
- Day 14: Final notice ("We need to resolve this: here are your options")
- Day 21+: Escalation (phone call, payment plan offer, or collections process)
The first four steps are fully automatable. Step 5 requires a human decision, but the automation can flag it for you.
Why this timing? Three days is long enough to not seem pushy but short enough to catch it while the work is still fresh in the client's mind. Seven days adds urgency without hostility. Fourteen days is the "this is serious" marker that triggers most people to act.
What Each Message Should Say
Your follow-up emails don't need to be long. They need to be clear, professional, and include a direct link to pay. Here's what works:
Day 3: The Gentle Nudge
Subject: Quick reminder: Invoice #1234 from [Your Business]
Hi [Name],
Just a friendly reminder that invoice #1234 for $2,500 was due on [date]. I know things get busy, so here's a quick link to take care of it:
[Pay Now Button/Link]
If you have any questions about the invoice, just reply to this email.
Thanks, [Your Name]
Day 7: The Firm Reminder
Subject: Invoice #1234 is now 7 days past due
Hi [Name],
I wanted to follow up on invoice #1234 for $2,500, which is now 7 days past due. I've attached the original invoice for your reference.
You can pay instantly here: [Pay Now Link]
If there's an issue with the invoice or you'd like to discuss payment arrangements, please let me know by [date].
Best, [Your Name]
Day 14: The Final Notice
Subject: Final notice: Invoice #1234: action required
Hi [Name],
This is a final reminder regarding invoice #1234 for $2,500, originally due on [date]. This invoice is now 14 days overdue.
Please arrange payment by [date, 7 days out]: [Pay Now Link]
If payment isn't received by that date, we'll need to discuss next steps. I'd much rather resolve this directly. Please reach out if there's anything preventing payment.
Regards, [Your Name]
Notice the progression: friendly → professional → urgent. The tone escalates, but it never gets hostile. You want to get paid AND keep the relationship.
Setting This Up With Stripe + Zapier
If you use Stripe for invoicing, here's the exact setup:
Trigger: Invoice Sent in Stripe
Zapier watches for new invoices in Stripe. When one is created and sent, the clock starts.
Zap 1: Day 3 Reminder
- Trigger: Schedule by Zapier (runs daily)
- Action 1: Find invoices in Stripe that are 3 days past due and still unpaid
- Action 2: Send reminder email via Gmail using the Day 3 template
- Action 3: Log the reminder in Google Sheets (for your records)
Zap 2: Day 7 Reminder
Same structure, filtered for invoices 7 days past due:
- Trigger: Schedule by Zapier (runs daily)
- Action 1: Find Stripe invoices 7 days past due
- Action 2: Send Day 7 email via Gmail
- Action 3: Update Google Sheets log
Zap 3: Day 14 Final Notice
- Trigger: Schedule by Zapier (runs daily)
- Action 1: Find Stripe invoices 14 days past due
- Action 2: Send Day 14 email via Gmail
- Action 3: Update Google Sheets log
- Action 4: Send you a Slack/email notification that a client has reached final notice stage
That notification in Zap 3 is important. At 14 days, you should personally review the situation before any escalation. The automation got you this far without any effort. Now it hands off to you for the judgment call.
Setting This Up With QuickBooks + n8n
If QuickBooks is your invoicing tool, n8n is a great fit because one workflow can handle the entire sequence:
Single n8n Workflow:
- Schedule Trigger: Runs once daily at 9:00 AM
- QuickBooks node: Fetches all unpaid invoices
- IF node: Branches based on days overdue:
- 3 days → Send gentle reminder email
- 7 days → Send firm reminder email
- 14 days → Send final notice email + notify you
- 21+ days → Add to "needs escalation" spreadsheet + urgent notification
- Gmail node: Sends the appropriate email with QuickBooks payment link
- Google Sheets node: Logs every action
The beauty of n8n here is the single workflow with branching logic. You can see the entire follow-up process in one visual flow. And since n8n doesn't charge per task, running this daily against all your invoices costs nothing extra. Not sure which platform is right for you? See our Zapier vs n8n comparison for a full breakdown.
What About Built-In Reminders?
Both Stripe and QuickBooks have built-in payment reminder features. QuickBooks lets you set up automatic reminders at intervals you choose. Stripe has a smart retries feature for failed payments and basic email reminders.
So why build a custom automation?
Control over messaging. Built-in reminders send generic emails from the platform. Your custom emails come from your business email address, match your tone, and include specific details about the work you did. They feel personal, even though they're automated.
Multi-channel follow-up. Your automation can send an email AND a text message AND a Slack notification to your team AND update your CRM, all at once. Built-in reminders just send an email.
Better tracking. When everything logs to a Google Sheet or your CRM (like HubSpot), you build a history. You can see which clients consistently pay late, which ones respond to the first reminder, and where your cash flow bottlenecks are.
Escalation logic. Built-in tools don't flag overdue accounts for human review or trigger different actions at different time intervals. Custom automations do.
That said, if you just want basic reminders and you're already on QuickBooks or Stripe, turn on their built-in features today. Something beats nothing. You can always upgrade to a custom automation later.
Tips for Getting Paid Faster
The automation handles timing and delivery. These tips improve the content:
Always include a direct payment link. Every reminder email should have a one-click path to pay. The more friction you add between "I should pay this" and payment confirmation, the more people fall off. Stripe and QuickBooks both generate shareable payment links.
Send invoices on Tuesday or Wednesday. Data consistently shows mid-week invoices get paid faster than Friday or Monday ones. Friday invoices get lost in the weekend. Monday invoices compete with the week's priorities.
Use clear payment terms upfront. "Due upon receipt" is vague. "Due within 15 days. Late payments subject to 1.5% monthly fee" is specific. Put your terms in your contract AND on the invoice.
Offer multiple payment methods. Credit card, ACH transfer, and even a "mail a check" option. Each barrier you remove speeds up payment. Stripe makes it easy to accept cards and bank transfers on the same invoice.
Consider early payment discounts. "2% discount if paid within 5 days" costs you $50 on a $2,500 invoice but gets you paid weeks earlier. For many businesses, the cash flow benefit far outweighs the discount.
Frequently Asked Questions
Won't automated reminders feel impersonal or damage client relationships?
Not if you write them well. The templates above are warm and professional. They read like you wrote them personally. Most clients actually appreciate reminders because they genuinely forgot. The alternative (you calling them awkwardly after 30 days) is far more uncomfortable for everyone. Automation makes the process consistent and removes the emotional weight from you.
What should I do when a client reaches the 21-day mark?
At 21 days, it's time for a personal phone call. The automation should alert you, not take action. On the call, be direct but empathetic: "I want to make sure there isn't an issue with the work or the invoice. Can we figure out a path to getting this resolved?" Offer a payment plan if needed. If the client is unresponsive after the call, consider a formal demand letter or a service like Fundbox or a collections agency, but that's a last resort.
How do I handle partial payments?
Both Stripe and QuickBooks track partial payments. Your automation should check the remaining balance, not just "paid/unpaid." Adjust your reminder templates to say "Your remaining balance of $X is past due" rather than the full invoice amount. This shows you're paying attention and keeps the communication accurate.
Is it legal to charge late fees?
In most U.S. states, yes, as long as the fee was disclosed in advance (in your contract or on the invoice) and is reasonable. A common standard is 1-1.5% per month on the overdue amount. Check your state's regulations and include late fee terms in your service agreement. The threat of a late fee often matters more than the fee itself. It communicates that you take payment terms seriously.