Cutting invoice processing from 17 hours to under one for a Sydney building contractor

The problem

The business was receiving around 80 supplier invoices per month. Every single one arrived as a PDF in the accounts email inbox. Every single one had to be opened, checked against the relevant purchase order, and entered into Xero line by line.

At roughly 13 minutes per invoice, that added up to around 17 hours per month. The person doing this was the owner's admin assistant — at $30/hour, the monthly cost of invoice entry alone was around $510.

Because she didn't have time to chase every discrepancy, invoices with mismatched amounts or missing purchase order numbers were sometimes getting passed through. The accountant was catching errors at month-end — which meant more back-and-forth, more corrections, and more stress.

What we built

A system that watches the accounts email inbox. When an invoice arrives, it reads the document automatically — pulling out the supplier name, invoice number, amounts, and line items — and checks them against the expected purchase order. If everything matches, it creates a draft entry in Xero formatted exactly the way the accountant needs it.

The admin opens Xero each morning and reviews a short list of drafts ready for approval. She scans them, approves the clean ones, and sends any with questions back to the supplier. The whole batch takes about 10 minutes.

Invoices the system isn't confident about — poor scan quality, a supplier it hasn't seen before, an amount that doesn't match — it flags those separately. She works through that list in about 5 minutes on a normal day. Nothing enters Xero without a human approving it first.

What we had to figure out

• About 1 in 8 invoices was a photo, not a proper PDF Some subcontractors send handwritten or photographed invoices. The quality varies a lot. Instead of guessing on low-confidence reads and risking wrong amounts, the system flags those for manual entry. The admin said it was a relief — she'd rather spend 2 minutes on a clear handoff than 10 minutes correcting a mistake.
• One supplier changed their invoice format without warning A supplier updated their template mid-project and the system stopped recognising their layout correctly. We built in a quarterly review reminder to check supplier templates. It takes about 20 minutes and catches format drift before it causes problems.
• Early on, every invoice went into one pile The first version sent everything — including invoices clearly needing human review — straight to the Xero approval queue. The admin couldn't tell clean invoices from uncertain ones at a glance. We split them into two separate lists. That fixed it immediately.