112 is an emergency number "by specification", it will always work (on GSM/UMTS/Vo LTE networks, NOT on landlines)), no matter what country you're in. I think this also applies to 911, although I'm not 100% sure about this.

Numbers like 000 are a different matter, there are scenarios in which they might not work even if you're in Australia (when you have a non-australian SIM or no SIM at all, for example).

For more about this, see e.g.

https://nickvsnetworking.com/tales-from-the-trenches-emergen...