I am travelling from Vancouver to auckland via SFO and Sydney. I will be in transit in Sydney, arriving on a UA flight and transiting to an Air NZ flight to Auckland. I have a medical condition and will be carrying 3 months supply of a controlled medication( not marijuana).They will be in my carry on bag as I need them to clear US customs in SFO. Will I be required to clear Australian customs as I am in transit to NZ?
Short answer: you do not provide sufficient information to answer the question.
The Australian Government Department of Home Affairs' webpage on this issue says:
If you are from an eligible country (see eligible countries listed below) you can transit through Australia on your way to a third country without an Australian visa provided you meet all of the following criteria:
- will arrive in Australia by aircraft
- have a confirmed ticket to leave Australia to travel to a third country by aircraft within 8 hours of arriving
- have valid travel documents to enter that country
- must not need to clear immigration or leave the airport transit lounge for any reason before boarding your onwards flight. Even if you meet all other criteria, including being of an eligible country, if you need to clear immigration, for example to collect or transfer baggage onto, and/or to board, your onwards flight, you will need an Australian visa to do this. For more information see Transit facilities at Australian airports.
If you are:
- a citizen of Andorra, Argentina, Austria, Belgium, Brunei, Bulgaria, Canada, Chile, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Federated States of Micronesia, Fiji, Finland, France, Germany, Greece, Hungary, Iceland, Indonesia, Ireland, Italy, Japan, Kiribati, Latvia, Liechtenstein, Lithuania, Luxembourg, Malaysia, Malta, Marshall Islands, Mexico, Monaco, Nauru, Netherlands, New Zealand, Norway, Oman, Palau, Papua New Guinea, Philippines, Poland, Portugal, Qatar, Romania, Samoa, San Marino, Singapore, Slovakia, Slovenia, Solomon Islands, South Africa, South Korea, Spain, Sweden, Switzerland, Thailand, Tonga, Tuvalu, United Arab Emirates, United Kingdom (including its colonies), United States of America, Uruguay, Vanuatu and Vatican
- a resident of Hong Kong who holds a Hong Kong Special Administrative Region (HKSAR) passport or a British National Overseas (BNO) passport
- a resident of Taiwan who holds a passport issued by the authorities of Taiwan (other than passports purported to be official or diplomatic passports)
- an Indian official passport holder
a diplomatic passport holder (This does not include holders of Arab Non-National Passports and diplomatic passports from Afghanistan, Algeria, Angola, Bahrain, Comoros, Democratic People's Republic of Korea, Egypt, Iran, Iraq, Jordan, Kuwait, Lebanon, Libya, Madagascar, Mauritania, Morocco, Pakistan, Russian Federation, Saudi Arabia, Sierra Leone, Somalia, Sudan, Syria, Tunisia, Yemen and Zimbabwe. These passport holders must get a visa.)
Note: This information is not applicable to stateless persons and refugees.
The linked page above (about airport transit facilities) says:
Some Australian airports have limited transit facilities. Airport limitations may mean that you will require an Australian visa such as a Transit (subclass 771) visa in order to clear immigration, even if you have met all other ‘transit without a visa’ (TWOV) requirements. The below information may assist you to decide whether you will need to clear immigration during your transit through Australia and will therefore need an Australian visa.
Sydney (SYD), Cairns (CNS), Gold Coast (OOL)
Do not operate on a 24 hour basis and overnight stays are not permitted. Passengers transiting overnight will need an appropriate visa for Australia to leave the airport to access overnight accommodation. There are airport transit lounge facilities that allow TWOV eligible passengers to connect to their onwards flight.
You did not disclose your citizenship or residence and type of travel document, nor the time frame of your Sydney airport transit, nor whether you hold valid entry documents for New Zealand. That information is required to determine if you can change flights in Sydney without passing through Australia immigration and customs.