I want to book travel for my family of 4 and upgrade to Polaris. I have 170K miles in my account (need 240K for the particular route we're looking at) and they have about 15-20K each. I know I have to transfer some Chase points in to make up the difference, but can I use some of their miles for free? Or do I have to pay to transfer their miles to my account to upgrade all 4 of us? I assume there's no way for me to avoid the fee by transferring some Chase points to each of their 3 accounts to pay for one outbound flight upgrade and then I use my miles to pay the other inbound flight upgrade.
Thanks!
P.S. I tried looking this up on the United website but the FAQ isn't very helpful. I see that it's a $15 fee per 1,000 miles, so transferring up to 60K miles from their 3 accounts into mine would cost me $900.