GST and duty on plastic sheet orders: who pays what, Australia vs offshore
How Australian GST, PNG GST and import duty are handled when Plastics Direct ships plastic sheet to Australian and offshore end customers — and why the delivery address decides the tax treatment.
One of the most common questions we get from new customers — especially buyers ordering into Papua New Guinea, the Pacific Islands or Southeast Asia — is a simple one: 'Will your invoice have GST on it, and if not, do I still have to pay tax somewhere?' The answer is straightforward once you know the rule, but it trips up plenty of first-time importers because Australian GST and destination-country GST are two separate taxes that never appear on the same invoice.
Here's how Plastics Direct handles it, worked out with our shipping and customs agent so every order lands cleanly on both sides of the border.
Rule of thumb: the delivery address decides the tax
Australian GST is a destination-based consumption tax. If the goods are delivered to an address inside Australia, the sale is domestic and 10% GST is added to our invoice. If the goods are exported — shipped from Australia to any offshore address — the sale is GST-free under the export rules in the GST Act, and our invoice shows no GST.
The billing address is irrelevant. A PNG-registered company with an Australian project site is invoiced with GST. An Australian company shipping to a mine-site in Lae is invoiced GST-free. What matters is where the plastic physically ends up.
Australian end customer: 10% GST on the invoice
For deliveries inside Australia, our invoice includes 10% GST as a separate line. If you're GST-registered, you claim it back through your next BAS — the net cost to your business is the ex-GST figure. Our shipping agent remits the GST component on our behalf, so there's nothing extra for you to handle beyond paying the invoice as issued.
This is the standard treatment whether you're a Sydney sign shop buying a pallet of acrylic, a Perth engineering workshop buying UHMWPE wear plate, or a Cairns marine fabricator buying HDPE. One invoice, GST included, claim it back if you're registered.
Offshore end customer (PNG, Pacific, Asia): GST-free invoice, taxes paid to destination customs
For orders shipping from Australia to a PNG address — Port Moresby, Lae, Madang, mine-sites, anywhere across the country — our invoice is issued without GST. That's not a discount; it's the correct export treatment. The 10% Australian GST doesn't apply because Australia isn't the country of consumption.
What does apply is PNG GST (currently 10%) and any applicable PNG import duty, both payable to PNG Customs when the container clears the port. Our shipping agent manages that clearance end-to-end: they lodge the customs entry, pay the PNG-side GST and duty on your behalf at the border, and invoice you separately for those taxes plus a clearance fee. You end up with two invoices — ours for the goods and freight, theirs for PNG taxes and clearance — but only one landed cost to reconcile.
The same pattern applies to other offshore destinations we ship to (Solomon Islands, Fiji, Vanuatu, New Caledonia, Indonesia, the Philippines): our invoice is GST-free, and the destination country's consumption tax and duty are paid to the local customs authority through our agent.
Why it's done this way
Layering Australian GST on top of PNG GST would mean the same shipment is taxed twice — once on the way out of Australia and again on the way into PNG. The export rules exist specifically to prevent that. As long as we hold evidence that the goods were exported (bill of lading, export declaration, customs documentation), the ATO accepts the sale as GST-free and PNG Customs collects the tax that actually applies at the destination.
That's why our export invoices always reference the container number, the port of discharge and the shipping agent — those documents are the audit trail that keeps the GST-free treatment defensible if the ATO ever asks.
Quick reference
Delivery inside Australia → our invoice includes 10% GST → claim back on BAS if registered.
Delivery to PNG or any offshore address → our invoice is GST-free → shipping agent pays PNG GST and duty at the border and invoices you for those separately.
Not sure which category you fall into, or ordering into a country we haven't shipped to before? Send us the delivery address before you place the order and we'll confirm the exact tax treatment in writing so there are no surprises when the container lands.