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Business Ops

Invoice Chaser.

A free Claude skill that drafts overdue-invoice reminder emails with the right amount of pressure — friendly nudge at day 3, firm reminder at day 14, final notice at day 30 — adjusted for who's paying and how they've paid before.

Free · MIT licensed · Works in Claude Code, Claude.ai & the API
What it does

Chasing money is a system, not a mood.

Most owners either send "just checking in!" forever or jump straight to threats. This skill gives Claude the escalation ladder a good bookkeeper runs by instinct.

  • Four escalation stages — nudge (1–7 days), firm reminder (8–21), final notice (22–45), formal demand (46+) — picked automatically from the due date.
  • History-aware tone — a loyal five-year client gets softer treatment than a chronic late payer at the same day count.
  • Owner-voice rules — under 120 words, one call to action, invoice linked every time, zero "sorry to bother you."
  • Edge cases handled — disputes, broken promises to pay, hardship payment plans, and the "is this even worth chasing" call.
  • Always plans the next touch — every draft comes with an "if no reply by [date]" follow-up plan, because chasing is a sequence.

Who it's for

Anyone who invoices and hates asking twice: contractors, landscapers, cleaners, designers, consultants, small agencies, bookkeepers chasing on a client's behalf.

If your accounts receivable lives in a spreadsheet and your reminders live in your head, this replaces the dread with a procedure.

What you say to trigger it

"This client hasn't paid in three weeks." · "Write a payment reminder for invoice #204." · "Who owes me money and how hard should I push?"

Example output

18 days overdue, decent customer, one nudge ignored.

You tell Claude: "Mark at Prairie Rock Landscaping still hasn't paid invoice #1042 — $1,850, due June 13. I sent a friendly reminder on the 20th, nothing." Here's what comes back:

Notice what's not there: no apology, no "hope you're well," no three competing asks. Fact, link, one question. That's the skill working.

How to install

Three ways in. All free.

Option 1 · Claude Code

One command

In your terminal, run:

npx skills add buildwithreef/claude-skills

Pick invoice-chaser from the list (or install the whole set). Done.

Option 2 · Claude.ai

Upload the zip

Download the .zip below, then in Claude.ai go to Settings → Capabilities → Skills and upload it.

Download invoice-chaser.zip

Option 3 · Manual

Copy the file

Copy the SKILL.md below into ~/.claude/skills/invoice-chaser/SKILL.md. The zip also includes the full email template library the skill references.

invoice-chaser/SKILL.md
---
name: invoice-chaser
description: Drafts overdue-invoice reminder emails that escalate in firmness based on how many days overdue the invoice is and the customer's payment history. Use when the user wants to chase an unpaid invoice, follow up on a late payment, or send a payment reminder — trigger phrases include "hasn't paid", "invoice is overdue", "payment reminder", "chase this invoice", and "who owes me money".
---

# Invoice Chaser

Draft payment-reminder emails that get invoices paid without burning the relationship. The core judgment call is matching pressure to the situation: enough firmness to get paid, never more than the history justifies.

## Step 1 — Gather the facts

Collect everything on this list before drafting. Never guess amounts or dates.

- [ ] Invoice number and amount
- [ ] Original due date → compute days overdue (today minus due date)
- [ ] Customer name and business
- [ ] Payment history: first-time customer / usually pays on time / chronically late
- [ ] Reminders already sent (how many, when, any response?)
- [ ] Any known dispute, hardship, or promise to pay
- [ ] How the customer can pay (payment link, check, card on file)
- [ ] Relationship value: is this a customer the user wants to keep?

If the user only says "they haven't paid," ask exactly two questions — "How many days overdue, and have you reminded them before?" — then draft with sensible assumptions stated at the top.

## Step 2 — Pick the escalation stage

| Days overdue | Stage | Posture |
|---|---|---|
| 1–7 | 1. Nudge | Friendly, assume oversight |
| 8–21 | 2. Firm reminder | Direct, ask for a payment date |
| 22–45 | 3. Final notice | Consequences named, deadline set |
| 46+ | 4. Demand | Last contact before collections or small claims |

Then adjust for history:

- **Good customer, first offense:** soften one stage. A 25-days-overdue invoice from a five-year client gets Stage 2 tone, not Stage 3.
- **Chronic late payer:** harden one stage, and never re-send a friendly nudge they have already ignored.
- **Ignored two or more reminders:** move up one stage regardless of day count.
- **Active dispute:** stop escalating entirely. Address the dispute first (see Edge cases).

## Step 3 — Write it

Rules that apply at every stage:

- Subject line = invoice number + amount + status. "Invoice #1042 ($1,850) — past due" beats "Following up!"
- Attach or link the invoice every single time. Never make them ask for it.
- One call to action: pay now, or reply with a payment date. Not both, not three.
- State days overdue as plain fact, without apology. No "sorry to bother you," no "just checking in."
- Keep it under 120 words through Stage 2; under 180 words after.
- Sign as the owner, from the owner's address. At small-business scale, email from "billing@" gets ignored.
- Never threaten anything the user will not actually do.

Full email templates for all four stages — plus dispute, broken-promise, and payment-plan variants — are in [references/templates.md](references/templates.md). Load that file before drafting.

## Step 4 — Deliver

Output in this format:

```
**Stage:** 2 — Firm reminder (18 days overdue, usually pays on time)
**Subject:** Invoice #1042 ($1,850) — 18 days past due

[email body]

**If no reply by [date, 5 business days out]:** send Stage 3.
Want me to draft it now so it's ready?
```

Always include the "if no reply" line — chasing is a sequence, not a one-off. Offer to draft the next stage in advance.

## Edge cases

- **They dispute the work:** do not send a reminder. Draft a reply that separates the disputed from the undisputed portion: "Happy to sort out [disputed item] — meanwhile the remaining $[amount] isn't in question. Can we get that settled this week?"
- **They promised to pay and didn't:** reference the promise with its date. This is Stage 3 regardless of day count: "On March 3 you said payment would go out that week."
- **They claim hardship:** offer a written payment plan with fixed dates and amounts, first payment small and immediate. $200 today beats $2,000 never.
- **Small amount, long overdue (under ~$200, 60+ days):** tell the user the truth — send one final demand, then weigh the cost of small claims or collections against writing it off and firing the customer.

## What not to do

- Don't mention lawyers or collections before Stage 4 (or a genuine Stage 3 final notice).
- Don't stack apologies or soften with exclamation marks.
- Don't send reminders more often than every 5 business days.
- Don't re-send the same email twice — every touch either escalates or adds new information (a payment plan offer, a deadline, a consequence).

---

Built by Reef — AI systems for small business → https://buildwithreef.com
FAQ

Claude skill for overdue invoices — common questions

Is there a Claude skill for chasing overdue invoices?

Yes — this one. Invoice Chaser is a free, open-source Claude skill that drafts payment reminder emails and picks the right firmness automatically: a friendly nudge at a few days overdue, a firm reminder with a date request after a week, a final notice with a real deadline after three weeks, and a formal demand past 45 days. It also adjusts tone for the customer's payment history.

How do I install the Invoice Chaser Claude skill?

Three ways: run npx skills add buildwithreef/claude-skills in your terminal and select invoice-chaser (Claude Code), upload the .zip from this page in Claude.ai under Settings → Capabilities → Skills, or copy the SKILL.md above into a folder at ~/.claude/skills/invoice-chaser/.

Does it work in Claude.ai or only in Claude Code?

Both. Skills are a standard Claude feature — this one works in Claude Code, in Claude.ai (paid plans support custom skill uploads), and via the Claude API.

Will the reminder emails sound like a robot wrote them?

No — the skill enforces small-business voice rules: emails come from the owner, stay under 120 words in the early stages, never say "just checking in" or apologize for asking, and always include the invoice and exactly one call to action. The templates come from real collections practice, not generic AI copy.

Is it really free?

Yes. MIT licensed, no signup, no catch. It's published by Reef, an Iowa-based studio that builds AI systems, websites, and automation for small businesses. If you'd rather have this whole workflow running automatically — reminders triggered straight from your books — that's the done-for-you work Reef takes on.

Related skills

Goes well with

From the builder

Want invoices chased automatically?

The skill drafts the emails — Reef builds systems where overdue invoices trigger the right reminder on their own, straight from your books. That's the done-for-you version.