Upvote:1
If all your flights are on a single ticket:
SAN-LAX-SYD
- In SAN, you’ll be “checked through” to your final destination.
- You will most likely receive both boarding passes
- Your bags will be tagged to your final destination
- You won’t see them again until SYD
- In LAX, you will arrive directly in the departures area, just go to your gate. Depending on your specific flights, you will arrive and depart from either terminal 7 or 8, but they are actually two piers of the same terminal, no need to go through security again
- You will not see your luggage in LAX
- And you’re off to SYD!
It’s more complex the other way around:
SYD-LAX-SAN
- In SYD you will be checked through to SAN
- You will likely get both boarding passes
- Your luggage will be tagged to SAN
- In LAX, you will arrive in TBIT, and will first go through passport control
- Then you will have to retrieve your bags
- Then go through customs
- Right after customs, drop your bags at the counter for this
- No need to go to check-in
- Go to your departure terminal
- Go through security
- Go to your gate
Note that while it’s possible to go through security between TBIT and Terminal 4, and then get to terminal 7 or 8 while remaining airside, that’s a pretty complex route which involves underground and overground passages. It’s probably a lot easier to get to Terminal 7 landside (outside security) and only go through security at Terminal 7 (but I’ve never done either, maybe someone has a different take on this).