Need help with fees for managing my brother-in-law's property

[Jon Fizette]

Hello, Bigger Pockets community! I live in Kansas City and have several rental properties that I manage myself. My brother-in-law is active duty in the Army and has lived in Kansas City for several years. In June of this year he will be assigned a new post, likely overseas, where he will serve out the remainder of his 20 years of service. He would like to keep his house in Kansas City, rent the house out while he's posted overseas, then plans to move back into the house once he's retired.

He has asked me if I would be interested in managing his property for him while he's gone since I have experience managing my own properties. I am planning on managing his property but we are trying to figure out the fee structure. Since they are family and we are very close with them I don't necessarily want to charge a monthly fee or percentage, but I also want to be able to charge a fair amount for my time. I would be managing their property for 8-9 years until he's retired and returns to Kansas City. I have checked the property management laws for the state of Kansas and they do not require a real estate broker license or a property management license for residential properties.

My question for the BP community is this: what is a fair amount to charge to manage the property for my family members? I've considered charging a flat fee per year, but knowing we will be managing this property for 8-9 years I am aware it will require a good amount of my time so I want to charge a fair amount. I would love your feedback! Thanks so much.