TPMS 'Registration'

I'm about to embark on buying some winter tires and wheels for my wife's current gen Rav. I'd rather get a full set of wheels than deal with annual remount/rebalance issues - plus then I can swap the tires myself. In the past I've had good luck with Tire Rack, but a comment on checkout has me a little confused. I can opt to have TPMS sensors installed, which I would do, but it also says them must be registered to the car at a service station. Is this true? Do I need to take the assembled wheels to a dealer to have them 'paired' with the car, or is it just a matter of pairing them using the dash vehicle TPMS setting options? If they do have to be paired by a service station or the dealer, do I have to unpair and repair every time I swap the tire sets? Seems kinda stupid if that's the case, but I figured I'd ask here before ordering. Any help would be appreciated! TIA

RR