What is a BAS? Australia's quarterly filing explained

Marek sells camping gear from Gdańsk, holds stock in Brisbane, and has just been told he has a BAS due. He has no idea what that is. By the end of this video he'll have watched one built, line by line, from a real quarter's numbers.

BAS stands for Business Activity Statement. It's the form registered businesses use to report and settle GST with the ATO. For most sellers it's quarterly. It is not an income tax return, it has nothing to do with profit, and it is much smaller than its reputation — the GST part is essentially four numbers.

A quick clarification, because the form has more on it than you'll use. A BAS can carry several taxes — PAYG instalments, PAYG withholding if you employ people in Australia, fuel credits, and others. A typical non-resident seller with no Australian staff uses the GST section and nothing else, so most of the form is blank and stays blank. If your BAS looks intimidating, it's usually because you're reading fields that don't apply to you.

The quarters run July to September, October to December, January to March, and April to June. Each is due twenty-eight days after it ends — so the twenty-eighth of October, April and July — except the December quarter, which gets until the twenty-eighth of February because of the holidays. Lodging through a registered agent generally buys additional time, which is a real and underrated benefit.

Now the four numbers. G1 is your total sales for the quarter. 1A is the GST included in those sales. 1B is the GST you paid on your own purchases and imports. And the last one isn't entered at all — it's 1A minus 1B, the net amount you pay or get back.

Marek's quarter. G1: eighty-eight thousand Australian dollars of sales through the marketplace. That's gross — before fees, before refunds, before anything is deducted. Sellers routinely put their payout figure here instead, and the payout figure is net of commission. It's the most common error on a do-it-yourself BAS.

1A: the GST inside those sales. Australian prices are GST-inclusive, so it isn't eighty-eight thousand times ten percent. It's the sales divided by eleven — eight thousand australian dollars. That divide-by-eleven catches every seller who's used to a tax added on top at checkout.

1B: GST on what he bought. Two shipments cleared customs that quarter and paid import GST at the border — three thousand one hundred dollars, on the freight invoices. Add GST on Australian-side costs where it applies. Call it three thousand four hundred.

Now the part that quietly corrupts more DIY statements than anything else: marketplace fees. Commission, fulfilment fees, storage, advertising — they're deducted before your payout, which is why the payout figure is wrong for G1. Whether GST applies to those fees depends on how the marketplace is itself registered and how it invoices you, and it is not safe to assume. Get it wrong in one direction and you overstate credits; wrong in the other and you leave money with the ATO. Read the tax invoice the marketplace issues you, not the summary.

Refunds and returns are the same family of problem. A refunded sale means the GST you reported on it comes back out, in the quarter the refund happens rather than the quarter of the sale. Do that properly and it self-corrects; ignore it and you're paying GST on revenue you gave back. For a category with a real return rate — apparel, electronics, anything sized — this is not a rounding error across a year.

So: eight thousand of GST on sales, minus three thousand four hundred of credits, leaves four thousand six hundred to pay. Not eight thousand — four thousand six hundred. The border credits took nearly half of it off, and they only exist because Marek is registered in the standard lane. Unregistered, that same three thousand four hundred would simply have been gone.

And it can go the other way. A quarter where Marek restocks heavily but sells through slowly — a big shipment in, modest sales out — can produce more credits than GST collected. The BAS is then a refund, and the ATO pays him. Sellers who assume a BAS is always a bill are often surprised by their restocking quarters.

What makes this take an afternoon instead of a weekend is records, and there are only three sources. Marketplace settlement reports for the sales side. Freight and customs paperwork for the import GST. Australian supplier invoices for anything else. Keep them as you go and the quarter assembles itself; go looking for them in the last week and it doesn't.

Miss one and there are failure-to-lodge penalties, charged in units for each period you're late, and they accrue whether or not you owed anything that quarter. A nil quarter still has to be lodged. That catches sellers who pause their Australian listings and assume the obligation pauses too — it doesn't, until the registration is cancelled.

Marek's quarter, in the end, took an afternoon. Pull three reports, fill four boxes, check the arithmetic, lodge, pay. Four times a year. It is genuinely not the monster it sounds like — the difficulty in a BAS is almost never the form, it's whether the records were kept.

You can lodge a BAS yourself — the ATO's online services walk through it, and for a clean quarter that's a reasonable afternoon's work. Where sellers hand it over is reconciliation: settlement reports that bundle fees, refunds and returns in ways that quietly corrupt G1, and import documents that don't match the shipment they belong to. The team at Epic Tax are Australian registered tax agents who run these quarterly for overseas sellers, including the extended agent lodgment dates. General information only, not tax advice.