Australian dual citizens have one rule above all others for Cambodia — pick a passport, apply on it, enter on it, exit on it. The 2026 specialist guide for AU+UK, AU+India, AU+Vietnam, AU+China, AU+NZ, and AU+Philippines duals.

Pick ONE passport for the whole trip and stick with it. Cambodian Immigration scans the same passport at entry and at exit — switching mid-trip causes problems every single time. For most AU duals (AU+UK, AU+India, AU+Vietnam, AU+China, AU+NZ), the Australian passport is the easier choice because the eVisa for Aussies is one of the simplest in SE Asia ($80 USD / ~$122 AUD all-in Tourist, 3 business days). But if your other passport offers visa-free entry or a cheaper visa fee, that's a legitimate alternative — just apply on it, and DON'T pull out the AU passport at the border.
The failure mode is not Cambodian policy. It is the mechanical reality that the entry stamp, the eVisa record, and the exit stamp all live on the same passport number. Aussie duals who try to be clever — entering on the Australian passport because the eVisa was easier, then exiting on the British or Vietnamese one because the next flight is cheaper — find out at the departure gate that the airline's system has no record of them entering Cambodia on that second passport. The plane leaves without them.
The rule is one sentence long. Pick the passport you will enter Cambodia with, apply for the visa on that passport's number, and present that same passport when you leave. Everything else in this article is consequences of that sentence — which passport is easier for each pair, what happens if you ignore the rule, what to show at the AU re-entry gate on the way home.
The table below covers the six AU dual-citizen pairs our desk sees most weeks. The 'easier choice' column reflects which passport tends to give the simplest end-to-end Cambodia trip, not which one is mandatory. You can legitimately use either passport you hold — just commit to one before you apply.
If you are weighing up which passport to use, four questions sort it in under a minute. One: does either passport give you visa-free entry to Cambodia? (Almost certainly no — none of the six pairs above qualify.) Two: does either passport cost less? (AU, UK, India, Philippines, NZ all pay the same $80 USD Tourist eVisa. China is a slightly different tier. Vietnam cannot use the eVisa at all.) Three: which passport are you flying out of Australia on, and which one will you re-enter Australia on? Four: which passport has more validity remaining? (Cambodia needs 6 months from arrival on whichever one you use.)
For five of the six pairs, the four questions land on 'use the Australian passport'. The exception is AU+NZ — both passports have identical fees and process for Cambodia, so the decision comes down to which one your AU outbound and re-entry happens on. Stay on whichever passport you left Australia on and the trip is a single clean record.
Three things, in order of severity. First, at the Cambodian exit gate, the immigration officer scans the passport you hand over and sees no matching entry record. They will pull you aside, ask for the other passport, and usually let you exit on whichever passport you actually entered on — but it adds 30-60 minutes minimum and in the worst case generates an irregular-exit note that can affect future visa applications.
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Erste Reise nach Kambodscha? Hier ist die ehrliche Checkliste für Erstbesucher aus Amerika — das Visum, die US-Dollar-Geldbesonderheit, die Sicherheitsrealität, die Impfungen, der Tempel-Kleidungsstil und wie die Ankunft am neuen Flughafen im Jahr 2026 tatsächlich aussieht.
Alle sieben Landgrenzen zwischen Thailand und Kambodscha sind seit Juni 2025 geschlossen, daher ist in 2026 der einzige Weg für Amerikaner, von Thailand nach Kambodscha zu gelangen, das Flugzeug. Hier erfahren Sie, wie die Routen Bangkok-nach-Siem Reap und Bangkok-nach-Phnom Penh funktionieren, welches Kambodscha eVisa Sie vor dem Boarding benötigen, und warum der alte Poipet-Überlandplan nicht mehr existiert.
Drei Möglichkeiten, die 310 Kilometer zwischen der Hauptstadt Kambodschas und Angkor Wat zurückzulegen: ein $15 Expressbus, ein 45-minütiger Flug oder eine langsame Flussfähre. Hier erfahren Sie, was jede Option für einen amerikanischen Reisenden tatsächlich kostet, wie lange sie dauert und welche zu Ihrer Reise passt.
Second, at the airline check-in counter, the gate agent runs your passport against the airline's TIMATIC system, which cross-checks Cambodian arrival data. If there is no entry record on the passport you handed over, TIMATIC flags it and the airline declines to issue your boarding pass. This is the most common failure point — it happens before you reach Cambodian Immigration at all.
Third, at the Australian re-entry gate, SmartGate or the manual booth processes the passport you hand over. If it's not the one DFAT recorded your departure on, the system flags an inconsistent travel record. It is not a crime, but it generates an audit query that can show up on future passport renewals. Avoidable with one consistent passport.

AU+Vietnam is the largest dual-citizen cohort in Australia after AU+UK, and the question we field weekly is identical — can I use my Vietnamese passport for the short hop from Ho Chi Minh City to Phnom Penh? The answer in 2026 is no, not via the eVisa, and that single fact almost always pushes AU+Vietnam duals onto the Australian passport for the whole Cambodia leg.

The three remaining major AU dual-citizen pairs each have a small twist worth knowing, even though the recommendation (use the Australian passport) is the same for all of them.
Indian passport holders are eligible for the Cambodia eVisa at the same $80 USD Tourist tier as Aussies, so on paper either passport works. In practice, two factors push AU+India duals onto the Australian passport. Indian passport holders sometimes hit additional airline-system checks even when the Cambodia visa is approved; the Australian passport avoids that friction. The second factor is the OCI card — Aussie-Indian duals often hold OCI rather than full Indian citizenship, in which case the question is moot. OCI is not a passport; use your Australian passport.
PRC passport holders use the same eVisa portal as Aussies, but the fee tier runs slightly differently — there is a small surcharge on PRC-issued passports that brings the all-in cost up by a few USD. The recommendation for AU+China duals is still the Australian passport, not because of the fee delta, but because Chinese passport holders sometimes face additional bilateral checks that the Australian passport does not trigger. HK SAR passport holders use the eVisa at the same tier as Aussies; AU+HK SAR is less common in our caseload than AU+PRC.

The dual-citizen rule for Cambodia continues all the way back to Australia. Whichever passport you used to leave Australia, DFAT recorded your departure on that passport. When you re-enter Australia, SmartGate or the manual booth needs to see the same passport — or it will process you cleanly but flag the inconsistency on your travel record.
If you entered Cambodia on your Australian passport, used it to exit Cambodia, and re-enter Australia on it, the loop is closed and the record is clean. This is the default we recommend for five of the six AU dual pairs, and it is the path of least resistance for everyone involved. DFAT has a complete record, your AU customs declaration matches the passport you departed on, and there are no hanging threads.

Five smaller situations that come up often enough to need a quick paragraph each.
The AU+Vietnam pair: use Vietnamese passport for Vietnam, Australian for Cambodia.
See the combo guide →Bangkok in, Siem Reap out — but the land border is closed in 2026.
Read the 2026 update →The overlooked third stop on the Indochina loop.
Plan the Laos route →Where most Aussies stop on the way through.
Sort the stopover →Bali or Cambodia for your next trip — or both?
Compare the two →