A system for determining when an occupant in a motor vehicle seat and restrained by a seatbelt restraint system has improper posture. The system and method include: a seatbelt buckle sensor, a seatbelt payout sensor, an occupant posture sensor. Moreover, a control module executes code to: determine the presence of the seatbelt latchplate in the seatbelt buckle, determine whether the difference between the first seatbelt payout length when the seatbelt is buckled and the second seatbelt payout length is greater than a seatbelt payout length threshold, compare the image of the occupant to at least one of a stored image and a posture zone when the seatbelt payout length threshold is exceeded, and determine whether the occupant has improper posture based on the comparison of the captured image of the occupant and the at least one of the stored image and the posture zone.