So you've got the Australia ETA sorted (or you're about to), and now you're staring at the "onward or return travel" question wondering if a one-way flight is going to be a problem. Short version: it can be, and it depends on which desk asks. The ETA (subclass 601) covers eligible passport holders from places like the UK, Japan, Singapore, several EU countries and beyond, applied for through an app before you fly, but the app approving you doesn't mean the airline or the Australian Border Force won't still ask what you're doing after your trip.

Here's what actually comes up, question by question.

Do I really need an onward ticket to fly into Australia?

Not always, but you should be ready to show one if asked. A dummy ticket, also called an onward ticket, is a genuine booking in the airline's system that proves you're planning to leave, without you paying for a flight you're not going to take. Border Force can ask for evidence of your onward or return travel as part of confirming you're a genuine visitor, something the UK Foreign Office's Australia travel advice touches on too, and a one-way ticket with no answer to "and after that?" is the kind of thing that turns a quick chat into a longer one.

Is the ETA different from a full visitor visa here?

Yes, and it matters for how this question gets asked. The ETA is a lighter-touch electronic authorisation for short eligible stays, usually tourism or business visits, and it's approved automatically most of the time. A full visitor visa application goes through an actual assessment, where a caseworker can ask directly for your travel itinerary as part of the paperwork. With the ETA, you mostly won't be asked until you're actually travelling, at check-in or at the border. With a visitor visa, it can come up earlier, in the application itself.

Will the airline check before I even board?

Often, yes. Airlines carry the cost of flying you back if you're refused entry at the other end, so check-in staff have a real incentive to confirm your documentation matches what's expected, sometimes cross-checked through systems like IATA's Timatic. If you show up with a one-way ticket and nothing else, don't be surprised if you're asked what your plan is before you're handed a boarding pass.

What if I'm one-way because I've got a working holiday visa lined up after?

This is genuinely common, and it's fine, but you still need to be able to explain and, ideally, show something. A working holiday visa changes your intent question (you're allowed to be there longer and to work) but it doesn't automatically satisfy "onward travel" on a tourist ETA leg if that's what you're travelling on first. If your visa situation is layered like this, keep the paperwork for each stage separate and know which document answers which question.

Does a hostel booking work instead of a flight booking?

No. Accommodation proof answers a different question (where you're staying) than onward travel does (that you're not staying indefinitely). Officers can and do ask for both separately. A hostel confirmation won't stand in for a bookable, checkable flight or onward reservation if that's specifically what's requested.

What should I actually book?

Option Satisfies onward-ticket ask Cost / flexibility
Generator PDF No, not a real PNR Free, but worthless if checked
Full paid return flight Yes Full fare, often non-refundable
Refundable flight held directly with an airline Yes, if cancelled within the free window Higher upfront cost, refundable
Short-hold onward ticket via a booking service Yes, it's a genuine PNR Small fee, no long-term commitment

The generator route is the one that actually creates risk, since it's the only option in that table with nothing real behind it if anyone looks. Everything else is a genuine booking with different trade-offs on cost and flexibility.

I'm coming and going a few times on the same ETA, does that change anything?

It changes what you need to think about each time, yes. An ETA can cover multiple entries within its validity, but every single arrival is its own check. A ticket you used to satisfy the question on your first entry doesn't carry over to your third, especially if it's already been flown or has expired. If you're bouncing in and out of Australia as a base for a longer regional trip, book a fresh onward reservation for each entry rather than assuming one document does the job repeatedly. It's a small extra step that keeps every arrival equally clean.

What actually happens if I get asked and I don't have anything?

Best case, you get a firm conversation and a warning. Worse case, you're looking at a more detailed secondary interview, and in genuinely unresolved situations, denied boarding before you've even left your departure airport. None of that is guaranteed to happen over a missing onward ticket alone, but it's the kind of avoidable risk that a five-minute booking removes entirely. There's no upside to leaving it to chance when the fix is this straightforward.

If you're routing through Asia first, Singapore's onward-ticket rule is worth a look before that leg, and if you want to double-check a booking yourself before you fly, here's how to verify your onward ticket PNR without a phone call.

Book an onward ticket that'll actually pass a real check at the gate.