If you log into his account, and click "My Account", the number you are most concerned with is the one under "Mileage Balance" in the blue box on the upper left. That's the number of miles you can spend.

If you use those miles to buy tickets that fly before 4/1/15, they will be treated the same as if you had your father's Plat status.

After that, they still can be changed/redeposited for free as long as your father maintains his plat status.


In the white box below the blue box, "Lifetime Flight Miles" will tell you the number of miles your father has towards his Million Miler status. If it is greater than 2,000,000, he has Platinum status for lif..... as long as United decides not to change their mind.