I think if I were to do this I would have had to have sent in some prepaid overpayment a little while ago. I expect a refund this year so the only reason I would pay would have been in case I were late on my taxes. I kinda was since I only just last week gave all my stuff to my tax accountant. He will have it ready to e file this week though so I am all set. (Lots went on in the MM household preventing me from doing things sooner--ie, new baby, etc ) So the pipedream of mile earnings by prepaying some huge amount is only just that. My financial advisor, however, is intrigued by my interest in miles. She always advises that people go for interest and avoid paying fees, but she says, hey, if you can find a way, all the power to ya! The tax guy likes hearing the ideas too but I think neither of them are going to tell me to DO such things while sitting in their offices. I just hope they do them on their own time at least because I hate it when I meet smart people who dont know about miles or how to take advantage of what's already out there. ie, if you see someone paying for something that could have been paid for with a mileage earning credit card.

To divert for a second, oh how many times have I seen some guy in line at Home Depot paying $600 in cash for stuff as I stand in line behind him wishing I could say, Hey dude, let me pay for that on my card here and you hand me the cash but you get the receipt...

Of course, if stuff like this happens to a great extent, maybe there'd be tax ramifications down the line (if it were say, $60,000)