How to do your BAS in Excel: a simple guide for Australian sole traders

For a lot of Australian sole traders, BAS time means a knot in the stomach and a shoebox of receipts. The good news is that you do not need an expensive monthly subscription to get it right. If you are registered for GST and your records are tidy, a well-built spreadsheet handles a quarterly BAS comfortably. Here is how it works, in plain English.

What is a BAS, and who has to lodge one?

A Business Activity Statement (BAS) is how you report and pay your GST to the ATO. If your business turnover is $75,000 or more you must register for GST, and once registered you lodge a BAS, usually every quarter. On it you tell the ATO how much GST you collected on your sales, how much GST you paid on your purchases, and the difference is either paid to the ATO or refunded to you.

If you are not registered for GST, you do not lodge a BAS at all, though it is still worth keeping clean records for your income tax return.

The BAS labels, in plain English

The BAS form uses short codes. For most sole traders only a handful matter:

• G1: your total sales for the quarter (GST inclusive).
• 1A: the GST you collected on those sales.
• 1B: the GST you paid on your business purchases.
• W1 and W2: wages paid and tax withheld, only if you have employees.
• 7D: fuel tax credits, if you are eligible (common for farm and transport businesses).

The amount you owe is simply 1A minus 1B. If 1B is larger, the ATO refunds you the difference.

The one GST rule that trips everyone up

GST is one eleventh of a GST-inclusive price, not ten percent of it. To find the GST inside a $110 sale, you divide by 11, which gives $10. A common mistake is to multiply the total by 10 percent, which gives the wrong figure. Build the divide-by-eleven rule into your spreadsheet once and it does the work for you on every line.

A simple system you can run in a spreadsheet

1. Record every sale as it happens, with the date, amount, and whether GST applies.
2. Record every business expense the same way, tagging the GST you paid.
3. At the end of the quarter, total the GST collected (that is your 1A) and the GST paid (your 1B).
4. Subtract 1B from 1A to find what you owe or are owed.
5. Copy those figures into your BAS in myGov, and lodge.

Common mistakes to avoid

• Claiming GST credits on things that have no GST, such as bank fees, residential rent, or most government charges.
• Using a flat 10 percent instead of dividing by 11.
• Never reconciling to the bank, so the figures quietly drift from reality.
• Leaving everything until the night before it is due.

A final note: this article is general information, not tax advice. Always check your own obligations with the ATO or a registered tax agent.