Invoicing from a Purchase Order
A real task from inside an Australian company: Claude reads a client's purchase order out of Gmail, builds a GST-correct invoice in QuickBooks, checks it to the cent — then turns the whole thing into a reusable Skill.
About this module. Module 3 taught the agentic suite in theory. Module 7 is that suite doing real, high-stakes work: a true, end-to-end account of running the books for Film Me Pty Ltd — a GST-registered Australian company — with Claude Cowork orchestrating and Claude in Chrome driving QuickBooks Online. Every number is real. So is the moment Claude catches a tax error a tired human would miss.
The job
One regular client — the Australian Institute of Management — sends a purchase order by email every time I run a workshop. For each one I have to log into QuickBooks, build an invoice that matches the PO exactly, and send it to their accounts team. It's repetitive, fiddly, and easy to get wrong — especially the GST.
So I asked Claude to do it. Working through the Claude in Chrome extension, Claude read the PO out of Gmail, opened QuickBooks, duplicated a previous invoice, mapped every detail across, checked the totals to the cent, and saved it ready for me to send.
Real money
Actual invoices to a real client, with GST that has to be right for BAS. Not a sandbox.
Multi-app
Spans Gmail, a PDF and a web accounting system — none built to talk to each other.
Repetitive, not mindless
Every PO is a little different, so you can't blindly copy. You have to read, interpret and map.
Reversible by design
The risky final step — emailing the client — stays with me. Claude builds and saves; I review and send.
The philosophy in one line: let the AI do the 95% that's tedious, and keep the 5% that needs your judgement. Claude builds and saves the invoice; you review and send it.
What Claude actually did, step by step
The real workflow Claude ran, end to end, for two purchase orders (#86785 and #86790). Tap any step to expand it.
Interactive: PO → Invoice Mapper
The skill of this task is mapping the purchase order onto the invoice correctly. Click a field from the PO (left) to see exactly where it lands on the QuickBooks invoice — and why it matters.
Select a field on the left to see where it goes.
The thing I always get wrong — and Claude caught
On PO #86785 there were two lines. When Claude added the second line, QuickBooks left the GST code blank — which would have undercharged the tax and made the invoice total wrong.
Second line added with no GST code. Tax undercharged; total doesn't match the PO.
Claude noticed the GST total didn't match, set the line to GST (10%), and the total snapped to the PO.
Why this matters: this is exactly the kind of silent error that slips past a tired human at tax time. Claude verified Subtotal, GST and Total against the PO to the cent before saving — and only moved on once they matched.
The part that compounds: turning it into a Skill
Doing the task once is useful. The real unlock is that Claude then wrote the whole procedure up as a reusable Skill — a saved set of instructions it can follow again. Now I just say "do the AIM invoice for PO 86785" and it runs the same way.
The Skill captures the hard-won details, not just the happy path:
The second PO took less effort than the first, and the next one will take less still. The work I did once became infrastructure. That's the difference between using AI as a calculator and using it to build yourself leverage.
What you can take from this
The honest take
I'm not a bookkeeper and I find this stuff stressful. Having Claude read the PO, build the invoice and check the GST for me removed both the time and the anxiety. The first time it caught a tax error I'd have missed, I was sold. ("Doing my taxes" here means day-to-day accounts and GST bookkeeping — not lodging a return. Always have a registered accountant review anything that goes to the ATO.)