The insured has a peak season endorsement adding 25% to its BPP coverage. The Peak Season endorsement is the CP 12 30 06 95. This increases the limit of insurance on BPP by 25% during the peak season. The policy also has a coinsurance provision at 90%. Assuming the loss occurred during a peak season, it would seem the policy limit was increased by 25% and that coinsurance should be reviewed utilizing the increased limit (limit in dec sheet plus 25%) and not the lower, off season, limit as stated in the dec sheet. Please give me your thoughts.

Michigan Subscriber

The peak season endorsement states that the limit of insurance on covered personal property is increased to include the amount shown in the Schedule.
As such, if the loss occurred during the time the peak season is in effect then the coinsurance should be applied using that increased amount, as you rightly surmised.