How to Record GST From Your Supplier Invoices for BAS — Without Retyping Every One

If you run a small business or do the books for a few, you know the BAS-time ritual: a folder full of supplier invoices — PDFs, email attachments, a few photos of paper receipts — and a spreadsheet where you type out the vendor, the total, and the GST, one invoice at a time. It's slow, it's easy to fat-finger a number, and it's the least valuable hour in your month.

The GST on those invoices is what lets you claim your GST credits, so it has to be right. This guide covers what the ATO actually requires, how GST is worked out, and a faster way to get the numbers off the page and into your accounting software.

First: is it a valid tax invoice?

You can only claim a GST credit if you hold a valid tax invoice for the purchase. Per business.gov.au and the ATO, a tax invoice for a sale under $1,000 must show:

• the words "tax invoice"
• the seller's business name
• the seller's ABN
• the date the invoice was issued
• a short description of what was sold (including quantity and price)
• the amount of GST payable (if any) — or a statement that the total price includes GST

For sales of $1,000 or more, the invoice must also include the buyer's identity or ABN.

One threshold worth remembering: for purchases of more than $82.50 (including GST), you need a valid tax invoice on hand to claim the GST credit. Below that, the rules are lighter — but keeping the record is still good practice.

How the GST amount is worked out

When GST applies, it's 10% — which means the GST portion of a GST-inclusive total is one eleventh (1/11th) of that total. A $220 invoice that includes GST has $20 of GST in it ($220 ÷ 11).

Most supplier tax invoices state the GST amount for you, and when they do, that stated figure is the one to record. Two things to watch:

• Mixed invoices. If an invoice has both taxable and GST-free items (some groceries, some services, an overseas charge), the GST is not simply 1/11th of the whole total — it only applies to the taxable portion. Use the GST line the supplier has broken out rather than dividing the grand total.
• GST-free or input-taxed suppliers. Not every invoice carries GST. A supplier who isn't registered for GST can't charge it, and some supplies are GST-free — so the correct figure is sometimes zero.

Why the record-keeping matters

The ATO generally expects you to keep these records for five years, and your BAS depends on them being accurate — the GST you report on purchases flows straight from the GST on the invoices you've captured. Get a number wrong and you either under-claim (leaving money on the table) or over-claim (a problem if you're ever reviewed). This is exactly why the manual-typing step is worth removing: fewer keystrokes, fewer transcription errors.

The faster way: extract, don't retype

Instead of reading each invoice and typing the fields into a spreadsheet, you can have the numbers pulled out for you. That's what Ledgr Invoice does: upload a PDF or image of a supplier invoice, and it reads back the vendor, the ABN, the invoice date, the line items, the GST amount, and the total — then lets you download it as a clean Excel or CSV file, or a CSV already formatted for importing into Xero.

A few things that matter for this specific job:

• It captures the ABN and GST as their own fields, so your spreadsheet is already in the shape your BAS working papers want.
• Your uploaded invoice is processed in memory and never stored on our servers — it isn't kept after the extraction runs. For financial documents, that's the privacy posture you want.
• No sign-up is needed to try it — you can run a real invoice through the live demo first.

What you should still check yourself

Automated extraction is a time-saver, not a replacement for a quick look. Outputs may not be 100% accurate — always verify the extracted GST and totals against the original invoice before you rely on them, especially on mixed or unusual invoices where the GST isn't a straight 1/11th. Treat the tool as the fast first pass that removes the typing, with your eyes on the final check.