Interesting thing I saw today when I logged into my United account. When I placed my cursor over the "Expiration" section under "My MileagePlus Summary" it opens up a small box which says that the miles never expire if: My Chase MileagePlus card is open, I have paid the annual fee, and the card is not in default. The system clearly sees that I have at least one of these credit cards, as it thanked me for having it. No where does it say anything about actually using the card (which I do, anyways). Hope this helps.