Sydney Airport says T1 International and T2/T3 Domestic are a short ride apart and cannot be walked between.
Complimentary terminal bus
The airport lists a complimentary Terminal Transfer Bus every 15 minutes between 05:30 and 22:30, with about a 10-minute trip.
Airline options may differ
Some airlines provide their own transfer process for eligible connecting passengers. Follow your airline instructions first when the itinerary is protected.
Self-transfer buffer
Separate tickets may require immigration, baggage collection, terminal transport, domestic check-in and security. Do not use only the 10-minute bus ride as your transfer estimate.
The published bus time is not the whole buffer
Sydney Airport’s complimentary terminal bus links T1 with T2/T3 and is currently listed at roughly 15-minute frequency with about a 10-minute trip during its operating window. A self-transfer still needs extra time for baggage, terminal access, check-in and security. Airline-provided transfer arrangements may differ, so follow the itinerary-specific instructions.
Sources and verification
Time-sensitive airport, airline, visa, security and transport details should always be confirmed with the relevant official source before travel.