Can the park charge residents for back-rent that was miscalculated because of the manager’s mistake?

 It depends on the situation. If the park rental agreement or lease stipulates the monthly rent for the term of the lease, and there is no provision in the lease for a contingency, such as an increase due to management error, then back-rent could not be charged. However, if residents have signed a rental agreement that provides that back-rent may be charged in the event of a management miscalculation or error, then the additional rent could be charged with a 90-day notice.

Recap:
● If not specified in lease or rental agreement, then collection of back-rent is not allowable.
● If back-rent is allowed under terms of lease or rental agreement, then a 90-day advance written notice is
required.