Changing property managers and bookings

[Gary563]

We own a property and we are changing property managers.

I offered the current PM his % of the up coming rentals and suggested he notify the guests about the change, give them a refund if he had to and have them contact the new property manager. I would have the new PM block their dates out and they could rebook for the same dates at the same price they paid but the current property managers says no he does not want to do this.

Are there any rules regarding this situation with rentals?

I really do not want to change the locks and leave guests hanging but the listing is not in my name the current PM listed himself as owner.

Thanks