Following Up on Unpaid Invoices
You're not losing money to bad clients. You're losing it to silence — the invoice you sent three weeks ago that you never followed up on because it felt awkward. Here's how Claude handles the awkward part so you get paid without burning relationships.
Before & After
You run a small plumbing company. You finished a $3,800 bathroom remodel three weeks ago. The customer was thrilled, shook your hand, said the check would be in the mail. It wasn't. You meant to call but Monday got busy, then Tuesday you had two emergency calls, and now it's been 22 days and bringing it up feels confrontational.
Meanwhile your supplier invoice for the fixtures is due in 8 days. You're floating someone else's project with your own cash.
Same week. Claude checks your Inbound tab every morning and flags the overdue invoice. It drafts a message in your voice: "Hey Mike, hope the new bathroom's treating you well. Just a heads up that invoice #247 from March is still showing open on my end — wanted to make sure it didn't slip through the cracks. Let me know if you need me to resend."
You review it, hit approve, and it goes out. Mike replies in two hours — turns out he lost the original invoice. Paid by Friday.
Why This Is Hard (And Why It Shouldn't Be)
Invoice follow-up is the most emotionally loaded task in a small business. You did the work. You delivered. Now you have to ask for money you already earned, and every day you wait makes it harder:
- Day 3: "I'll give them a few more days."
- Day 10: "Now it's been too long, it'll be awkward."
- Day 21: "If I bring it up now they'll think I'm desperate."
- Day 45: "At this point I'd rather eat the loss than have the conversation."
This is not a discipline problem. It's an emotional friction problem. The fix is to take yourself out of the drafting loop. Claude writes the message, you just decide yes or no. The awkwardness disappears when you're editing someone else's words instead of composing your own.
What You Need
- Your Two-Tab Sheet — with real Inbound data including Amount, Status, and Date Sent columns (set it up here)
- Claude Desktop — connected to your sheet via MCP
- 20 minutes — to set up the prompts, capture your voice, and test the first follow-up
Add Payment Tracking Columns
Your Inbound tab already tracks quotes and invoices. To handle follow-ups on unpaid invoices specifically, add two columns:
| Column | What it tracks | Example |
|---|---|---|
| Invoice Date | When the invoice was sent | 2026-03-20 |
| Payment Terms | When payment is due | Net 30 / Due on receipt / Net 15 |
Teach Claude Your Collection Voice
Following up on invoices requires a different voice than following up on quotes. Quotes are sales. Invoices are collection. You need to be warm but clear — there's no ambiguity about whether money is owed.
Tell Claude:
Then paste one or two real messages you've sent about overdue payments. If you've never sent one (that's the whole problem, right?), describe how you'd say it in person — Claude can work from that.
Set Up the Invoice Check
Tell Claude:
• 1–7 days past due: friendly reminder, assume they forgot
• 8–21 days past due: direct check-in, ask if there's an issue
• 22+ days past due: firm but professional, reference the specific invoice and amount
Show me each draft with the customer name, amount, and how many days overdue. Don't send anything."
Claude reads your sheet, calculates how overdue each invoice is, and drafts a message at the right tone. You see everything before it goes anywhere.
Review and Approve
Claude shows you each draft with context. For each one:
Looks right. Copy to email or let Claude send via MCP.
"Make it warmer" or "mention we did extra work on their order."
Not today. Push the follow-up date out and check again later.
After each action, Claude updates your Inbound tab — marking the follow-up date, logging that a message was sent, and scheduling the next check-in.
Save It as a Skill
Once you're happy with how the follow-ups sound, tell Claude:
Your new morning routine: "Check invoices." Claude finds what's overdue, drafts the nudges, you approve the ones that look right. Three minutes, and nothing slips through the cracks.
The Three Urgency Tiers
Here's what Claude's drafts look like at each level. Your voice profile adjusts the language so it sounds like you, not like a collection agency.
What You've Built
- An automated daily check for overdue invoices
- Three escalating tiers so the tone matches how overdue the invoice is
- A voice profile tuned for collection (warm but clear)
- Human-in-the-loop approval — nothing sends without you saying yes
- Automatic tracking so every follow-up is logged and the next one is scheduled
Most small businesses write off 5–15% of their invoiced revenue to "it's been too long to bring it up." That stops today. Two words every morning, and the money you earned actually makes it to your bank account.
What's Next?
Email Triage
Stop letting important emails drown in the noise. Claude sorts what matters.
Read the GuideWant your collection voice tuned and the skill set up on your machine?
Book a Starter Session (90 min)Or do it yourself — everything on this page is free.
Skill: Following Up on Unpaid Invoices
What this is for: Walk a small business owner through setting up a system where Claude reads their Inbound tab, finds overdue invoices, and drafts follow-up messages at three urgency tiers — in the user's own voice. Nothing sends without the user's approval. This solves the emotional friction of asking for money you've already earned.
When to use this: When a user asks their AI assistant to help set up this workflow. The user should explicitly authorize use of this skill by referencing this page URL.