Categorise expenses from a bank export

It's BAS time, and you've got a bank export with 400 transactions and no idea what half of them were. 'SQ *JOES' could be coffee, could be materials. You're dreading it.

The prompt

Here's a CSV of bank transactions: [upload]. Suggest a category for each from this list: [your categories]. Mark anything you're unsure of as 'CHECK'. Don't change amounts.

Replace everything in [square brackets] with your own details. Don't paste in anything you wouldn't want stored by the AI provider.

Steps

1. Export transactions (remove account numbers).
2. Upload and run the prompt.
3. Review every 'CHECK' row.
4. Use it to tidy up in your accounting software, or hand to your bookkeeper.

A worked example

A Brisbane graphic designer exports three months of transactions as a CSV and removes account numbers. She uploads it to ChatGPT with her list of categories (software, equipment, travel, meals, home office, personal) and asks it to suggest a category for each, flag anything it's unsure about, and note which might include GST.

It categorises most of them and flags 38 as unclear. She sorts those herself in 20 minutes. Then she uses the result as a guide while reconciling in Xero, rather than uploading it anywhere.

Where it goes wrong

AI guesses. 'Bunnings' could be materials or a personal BBQ. Never accept its categories blindly for tax purposes. It may also guess wrongly about GST, especially for overseas software. Check the flagged items and anything large.

Time saved

Categorising a quarter's transactions can take 1 to 3 hours. AI cuts the first pass to minutes; you spend your time on the tricky ones. These are my estimates for a typical small business, not measured results.

What it costs (AUD)

Xero and MYOB already suggest categories automatically (Xero's JAX on current plans, MYOB's Category Suggestions on all plans). If you're on those, use the built-in tools first. A free AI plan is fine for the occasional bank export.

The free plans of ChatGPT, Claude and Gemini handle this fine. If you end up using AI every day, the paid plans are roughly: ChatGPT Plus approx. A$30 a month, Claude Pro approx. A$29 a month billed monthly (US$20, or about A$24 a month if you pay yearly), and Google AI Pro approx. A$33 a month through the App Store. Prices approx., October 2026. Some are billed in US dollars, so your bank may add a foreign transaction fee. Check the vendor's pricing page before you buy.

Australian notes

GST: only claim GST credits where you have a valid tax invoice and the purchase is for business use. AI can't tell whether a purchase was business or personal. You have to. Your BAS agent or accountant has the final say. Remove account numbers before uploading bank data.

Privacy: the Privacy Act and the Australian Privacy Principles (APPs) cover most businesses turning over more than $3 million, plus some smaller ones such as health providers. Even if you're under the threshold, treat customer details with care: strip names, phone numbers and addresses before you paste anything into an AI tool.

My verdict

Helpful, but your accounting software's bank rules may do this better. Try those first.

Common questions

Can AI do my BAS?

No. It can help you sort transactions, but lodge your BAS yourself or through a registered BAS or tax agent.

Is it safe to upload bank statements?

Remove account numbers and names first, or use your accounting software's built-in tools instead.

What about GST on overseas subscriptions?

It depends on the supplier and whether they charge Australian GST. Check the invoice and ask your accountant.

Do this today

Export last month's transactions, remove the account details, and ask AI to suggest categories. Then compare with what Xero or MYOB suggests.

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