Like most other FTers, I charge everything I can in my program's (AA, MR, SPG) credit cards. I pay off my Citibank AA card about 4 or 5 times a month, so it spends a good amount of time at 2x its limit, however, I make sure to use it for my AA.com purchases to get bonus miles.
What to do if you *have* to buy tickets today but that AA Citi card won't have space until tomorrow?
Up until very recently there was a loophole on AA.com that would allow you to put a ticket on hold, essentially, until the day of departure. I flew every single time I did this, but it was also a good way to hedge on change fees if you were buying non-refundable tickets (Agent: "Oh, this isn't even ticketed!!! Let me make you a new one."). I never posted because (1) I thought AA would close the loophole and (2) I thought people would abuse it, using it as a sort of perma-hold if they didn't know if they were traveling or not.
Here is how it works:
1.) Pick a flight
2.) Place flight on hold
3.) (+24hrs) Purchase the flight
4.) When inputting your card, use the wrong expiration or CVV2 (CVV2 was only collected after a revision maybe 1 year ago or so).
AA runs credit cars a few hours after submission on the website. You can see that the status changes to "Purchased" after you submit and a few hours later to "Ticketed". During this time, your card is actually charged. If it declines, AA will try to reach you by telephone. If you ignore these calls, at least for EXPs (I got this to work for 2 other people), they will leave the reservation "Purchased" until you either call in or check in. At that time, you must pay.
Last weekend I bought about $4k worth of Flights for June. That killed the Citi card. I tried the wrong expiration date/Cvv2 trick, but AA rejected the card right away. I thought, oh well, I'll just wait until it maxes out and then make up the rest later by calling in.
I made a payment on Monday. Tuesday at 4am, AA charged my card (I was actually going to make good on the tickets after I hawked any reimburseable expenses to be picked up early this week for more miles for me.
). It appears that AA is both preauthorizing cars for $1 now *AND* continuing to charge the card until they get payment.
I don't know how many people knew about this loophole, but I sure as heck would imagine nobody was talking about it. Regardless, it is gone now.