passport rules for arriving / leaving a country

[Myrna]

We have 2 passports AU and UK. What are the rules for using them when travelling? Must we use the same passports when arrive and depart a country - so we don't fall foul of the immi / visa fee system?

Say, we leave Australia with AU passports.
Arrive country A with AU passports, leave country A with AU passports.
Arrive country B with UK passports (because country B does not charge a visa fee for UK passports, but charges a visa fee for AU passports), leave country B with UK passports.
Arrive country C with AU passports, leave country C with AU passports.
Arrive back in Australia with AU passports.

Are the above correct?

 

[MEL_Traveller]

We have 2 passports AU and UK. What are the rules for using them when travelling? Must we use the same passports when arrive and depart a country - so we don't fall foul of the immi / visa fee system?

Say, we leave Australia with AU passports.
Arrive country A with AU passports, leave country A with AU passports.
Arrive country B with UK passports (because country B does not charge a visa fee for UK passports, but charges a visa fee for AU passports), leave country B with UK passports.
Arrive country C with AU passports, leave country C with AU passports.
Arrive back in Australia with AU passports.

Are the above correct?

Yup! All good.

You’ll have to show your UK passport during check-in when you leave country A.