If you’re a UK–Australian dual citizen, trying to enter the UK on an Australian passport can cause problems at check-in or the border, because dual citizens are generally expected to use a British passport or a Certificate of Entitlement attached to the Australian passport. UK government travel advice says British-Australian dual nationals should enter the UK on a British passport, and the Australian High Commission says dual British/Australian citizens must enter the UK on their British passport or with a Certificate of Entitlement.

What usually happens

  • You may be denied boarding by the airline if you don’t have the right document.
  • If you do get to the UK border on an Australian passport alone, you can face delays and additional checks.
  • A UK ETA is not the solution for a dual UK-Australian citizen, because dual citizens are not meant to use an ETA to enter the UK.

What to use instead

  • A valid British passport.
  • A Certificate of Entitlement in your Australian passport.
  • In some urgent cases, temporary or emergency travel document options may apply.

Practical note

There have been recent rule changes tightening how dual citizens board UK- bound flights, and travel advice now explicitly warns that dual nationals may be refused boarding without the proper document.

Best next step

For this situation, the safest move is to travel with your British passport, or sort out a Certificate of Entitlement before flying.

TL;DR: a UK–Australian dual citizen should not rely on an Australian passport alone to enter the UK; use a British passport or a valid Certificate of Entitlement instead.