Hot tub electrical requirements are the strictest in residential code, for the obvious reason: nowhere else do 240 volts and standing water share a backyard on purpose. Every rule below exists because of that combination, and knowing them before the tub is bought is the difference between a smooth install and a spa sitting dry in the driveway.
The hot tub electrical requirements themselves
A dedicated circuit. Full-size spas draw 40 to 60 amps at 240 volts and share with nothing. The little plug-and-play tubs are the only exception, and even they want their own outlet.
GFCI protection for the whole circuit. Not a courtesy, the code. The ground fault device is what stands between a fault in the tub and the people in it.
A disconnect within sight of the tub. So anyone servicing it can kill the power themselves and see that nobody restores it behind their back.
A proper buried run. The cable crossing the yard goes down at required depth, and that trench is often the largest line on the quote, which is why the tub’s location is a pricing question, not a detail.
The question to ask before the showroom
Can your service carry it? A spa is one of the largest loads a house can add. On 200 amps, usually yes. On a 100 amp service already running a heat pump and an electric water heater, frequently no, and the answer then is a panel upgrade or a smaller tub. The load calculation takes minutes; do it first and shop with the answer in hand.
Decks, gazebos and second thoughts
Tubs on structures bring extra geometry about where the disconnect and nearby receptacles may sit. Planned before the deck is framed, it is all routine. Tell us where the tub is going, and if a shed, charger or yard lighting is plausible someday, the hot tub wiring trench can carry conduit for it for almost nothing while it is open.