Basic single zone Australian swim spa baths come with a 15 amp power cord that can be plugged into to a 15 amp dedicated power point. You can remove the cord and hard wire it with a 15 amp power supply and isolation (on/off) switch if you wish.
Single zone swim hot tubs with 2 or 3 jet pumps require a 32 amp direct wired power supply (and isolation switch) and dual zone and professional swimming spa baths require up to 60 amps (dual zone swim hot tubs will supply two separate power supplies).
If you are planning for a heat pump then you may need a separate power supply. This is not the case if the outdoor spa bath has a “Spa Net” brand controller (fully heat pump compatible). Gas heaters will need a separate 10 amp power supply.
It is the responsibility of the outdoor spa owner (or retailer) to use a Registered Electrical Contractor (REC) to install all relevant power requirements for your hot tub to the relevant codes and standards.
Upon completion of the work, your REC is required to supply you with an Electrical Safety Certificate.