The Awkwardness of Chasing Money
Almost every small business owner says the same thing about invoice follow-up: they hate doing it, so they avoid it, so invoices stay unpaid longer than they should.
It's not laziness. It's the friction of the task. Checking Xero or MYOB, figuring out who's overdue, writing a message that's firm enough to prompt payment but not so blunt it damages the relationship — then doing the same thing again two weeks later if they still haven't paid. Per invoice, this takes 15–20 minutes. Across a month's worth of late payers, it's easily 2+ hours of uncomfortable admin.
The automation below removes almost all of that. The follow-ups go out consistently, on schedule, in a tone that sounds like you — without you having to think about it. You only get involved when something needs a judgment call.
How the Automation Works
The workflow has three layers based on how overdue an invoice is:
Layer 1 (7–14 days overdue): Friendly reminder, fully automated. A polite email goes out automatically — personalised with the client's name, your invoice number, the amount, and a payment link. No human review required. This catches the majority of late payers who simply forgot.
Layer 2 (15–28 days overdue): Firmer follow-up, reviewed before sending. A second email is drafted by AI and held for your review each Monday morning. Slightly more direct tone. You read it, make any adjustments, and hit send. The AI writes it; you approve it.
Layer 3 (29+ days overdue): Flagged for a phone call. These land in a flagged list that you or your admin assistant works through. At this point, the relationship context matters enough that automation shouldn't handle it alone. The system just makes sure nothing falls through the cracks.
What You Need
- Your accounting software connected via API. Xero and MYOB both have APIs that tools like n8n, Make, and Zapier can connect to natively. If you're on something else, check whether it has a Zapier integration.
- n8n, Make, or Zapier for the workflow automation. n8n is the most flexible and cheapest at scale; Zapier is easiest to set up quickly.
- Claude API access (or GPT-4 API) for drafting the personalised emails.
- Your email sending setup — Gmail, Outlook, or a transactional email service like SendGrid.
If you're not technical, Make or Zapier is the path of least resistance. If you're comfortable with a bit of JSON and want more control, n8n.
Building It in n8n
Here's the workflow structure:
Trigger: Schedule node set to run every Monday morning at 8am.
Step 1 — Pull overdue invoices from Xero. Use the Xero node to fetch all invoices where status = AUTHORISED (sent but unpaid) and due date is in the past. This returns a list with client name, email, invoice number, amount, and days overdue.
Step 2 — Split by overdue bucket. Use an IF node to split the list:
- Days overdue < 15 → Layer 1 path
- Days overdue 15–28 → Layer 2 path
- Days overdue ≥ 29 → Layer 3 path
Step 3a — Layer 1: Draft and send automatically. Feed each invoice into a Claude API node with this prompt:
"Write a short, friendly payment reminder email. Client name: . Invoice number: . Amount: $ AUD. This is the first reminder. Tone: warm, not pushy. Include a sentence asking them to let me know if there are any issues. Sign off as [Your Name] from [Your Business]. Max 80 words."
Connect the output to your Gmail/Outlook send node. Done — it goes out automatically.
Step 3b — Layer 2: Draft and hold for review. Same Claude API prompt but with a slightly adjusted tone instruction: "This is a follow-up to a reminder sent two weeks ago. Politely but clearly ask for payment or an update on when to expect it."
Instead of sending, append the draft to a Google Doc or Sheet titled "Invoice follow-ups for review — [week]." Your Monday morning task is to open that doc, read each draft, adjust anything that needs adjusting, and send.
Step 3c — Layer 3: Flag for call. Send yourself (or your admin assistant) a summary email: "These invoices are 29+ days overdue and need a phone call this week." List the client, invoice number, amount, and a direct link to the invoice in Xero.
The Prompt That Doesn't Sound Like a Robot
The quality of your follow-up emails depends entirely on the prompt. Generic prompts produce generic emails — and clients can tell.
The things that make a follow-up email feel human:
- It uses the client's actual name (not "Dear Client")
- It references the specific invoice number and amount
- It leaves room for the client to explain if there's a problem
- It's short — three or four sentences, not a paragraph of corporate language
- It sounds like the person they've been working with
Here's the full Layer 1 prompt that works well:
"Write a short payment reminder email. Use this information:
- Client first name:
- Invoice number:
- Amount outstanding: $ AUD
- Invoice was due days ago
Keep it friendly and brief. Mention the invoice number and amount. Include one sentence leaving the door open if they have any questions or issues. Do not use phrases like 'As per our records' or 'Please be advised'. Sign off as [Your Name].
Max 75 words."
For Layer 2, adjust the final instruction: "This is a follow-up to an earlier reminder. Be polite but make clear that prompt payment would be appreciated. Same length and tone."
What the Numbers Look Like
The direct time saving is meaningful, but the bigger gain is consistency. Manual follow-up gets skipped when you're busy. Automated follow-up doesn't. That consistency is what actually reduces your average days-to-payment.
Most small businesses that implement this see a meaningful drop in their aged receivables within the first month — not because the automation is persuasive, but because a prompt sent on day 7 gets paid faster than one sent on day 24 when you finally got around to it.
The Parts You Still Own
This automation doesn't replace your judgment — it handles the mechanical part so your judgment is reserved for where it's needed.
You still decide:
- Whether to extend payment terms for a client going through something difficult
- How to handle a client who disputes an invoice
- When a relationship is at risk and the follow-up approach needs to change
- Whether to escalate to formal debt collection
The Layer 2 review step is there specifically so you can override the automated draft when a client's situation calls for something different. Don't skip the review. It's what keeps the automation from being tone-deaf.
Getting It Set Up
The fastest path is to start with just Layer 1 — the automatic 7-day reminder — and nothing else. Get that working first. Check it for two or three invoices to make sure the email content looks right and is actually going out.
Once that's running reliably, add Layer 2 (the Monday review queue). Then Layer 3 (the call-flag email) last.
The whole thing takes 3–5 hours to build if you're comfortable with n8n or Make. If you're new to these tools, budget a day and follow the platform's documentation carefully for the accounting software connection — that step trips people up most often.
After that: it runs every Monday without you touching it, your follow-ups go out on schedule, and you spend your Monday mornings on things that actually need your attention.