Most newer vehicles are equipped with seat belt warning chimes. Toyotas are no exception. The seat belt warning chime can easily be disabled. Disabling the alarm is not illegal, in fact, the instructions can be found in your owner's manual. Follow the procedure outlined to disable the seat belt alarm in most 2004 and newer Toyota vehicles.
Insert your key into the ignition and turn it to the "On" position. Do not crank the engine.
Press the small knob on your instrument cluster to cycle between your trip odometer and your odometer reading. Press the knob until it displays "ODO." Turn the ignition to the "Off" position.
Turn the ignition back to the "On" position and hold the small knob for 10 to 15 seconds. After the time has passed, put on your seat belt (while holding the knob).
Release the trip odometer knob to finish. Your instrument cluster will display "B off."
Perform the exact procedure again to enable the seat belt warning.
In many states, wearing your seat belt is required by law.