Vehicle payload is the capacity in terms of weight that a vehicle is able to carry but does not include the weight of the vehicle itself. Most of the vehicle certifications include information on payload which is determined by the cargo the vehicle can carry and the passenger weight. It is determined by how much weight a vehicle can carry without causing damage to itself or the road. The maximum payload for your vehicle can be found on the Tyre and loading label on the B-Pillar or the edge of the driver door.
Look for "THE COMBINED WEIGHT OF OCCUPANTS AND CARGO SHOULD NEVER EXCEED XXX kg OR XXX lb." for maximum payload. The payload listed on the label is the maximum payload for the vehicle as built by the assembly plant.
If you install any aftermarket or authorised-dealer installed equipment on the vehicle, you must subtract the weight of the equipment from the payload listed on the Tyre and loading label in order to determine the new payload.