Kitson Invoice Follow-Up Coach: Invoice Ageing and Kind Reminders You Send Yourself (Opus 5.5)

The work is finished. The invoice is still waiting.

Following up can feel awkward, and an overdue list doesn't tell you which balance to look at first or what to say. Kitson Invoice Follow-Up Coach reads your own invoice export, on your computer, and gives you:

• An ageing report: open invoices grouped by how long they are overdue (current, 1-30, 31-60, 61-90, over 90 days), by currency and by customer. Every currency is kept separate; nothing is converted.

• Each customer's payment pattern from your own paid invoices (for example "paid 41, 41 and 41 days after the invoice date"), days sales outstanding, and customer statements. Credit notes and payments are applied first.

• An expected-cash view: an estimate, week by week, from each customer's own timing. It is an estimate, not money in the bank.

• The one invoice to look at first, and a suggested reminder stage for each overdue invoice, worked out from your terms and how late it is.

• Then Claude Opus 5.5 drafts a kind reminder for each invoice that is ready for one, plus a short review. The app checks every amount and date in Claude's text against its own figures.

What makes it careful

• It never sends, schedules or calls anyone. You read each draft, change what you like and send it from your own email.

• Invoices your file marks as disputed, do-not-contact or on a payment plan are held back: no reminder is drafted for them.

• No threats, legal or collection words, or pressure. A late fee or interest is mentioned only when your own written terms give one, word for word, and only for business customers.

• Your files stay on your computer. Only totals per currency, the expected-cash estimate, the held-back count and total, and for each invoice ready for a reminder a code (I-001), the customer type, balance, dates, reminder stage, your written terms and a payment-pattern summary go to Anthropic. No customer name, invoice number, contact detail or note is sent, and nothing is sent to Kitson Workshop. Names are added back on your computer after drafting. You can see exactly what will be sent before you run it.

• The cost is shown before every run. In our own test on the made-up sample (eleven invoices and a credit note in two currencies), one run cost about 6 cents on our own Anthropic account. A bigger file costs a little more.

• Take it with you: a Word report (ageing and review), a Word reminder pack, the reminder drafts as a CSV, every table in Excel, and a calendar file of reminders for you (never messages to customers).

What you need

• Free Node.js 18+ (Windows, Mac or Linux).

• Your own invoice export as a CSV file (from QuickBooks, Xero, FreshBooks, Wave, Zoho or a spreadsheet saved as CSV) and your own written payment terms. Paid invoices in the file help with payment patterns and expected cash. A made-up sample is in the zip so you can try it first.

• Your own Anthropic account and API key, with a little credit. A Claude chat subscription does not include API access.

You pay Anthropic directly for what you use, on top of the price of the app.

Watch Biz's review: https://youtu.be/QK151wfhFxU

Early release, for educational purposes, made by Kitson Workshop. It works only from your own export and the terms you type in: it can misread or miss things. Check every figure and draft against your own records before you send or rely on it. Rules for consumer invoices and collections vary by place; this is a planning aid, not legal advice. If we can't get the app running for you, email kit376351@gmail.com within 14 days for a refund of the app price. Fixes are sent to buyers free. Kitson Workshop is not affiliated with or endorsed by Anthropic.