Not sure about Saks, but I can tell you what NM does (it's probably similiar and pretty sneaky). I got an expensive purse on an NM 6 month no interest promo and wrote down on my calendar when the 6-month date was, so I could pay it off without incurring the accumulated interest (which they do hit you with, if you don't pay it off in the designated time frame). I sent $1000 to cover the purse in its entirety as my payment that month, thinking that was all I had to do. I checked on line the day before the 6 months was up and NONE of the grand had been applied to my purse balance!! So I called and was told by CS that you have to SPECIFY that you want the $$$ to payoff the promo item, otherwise they just apply to general balance and would have hit me with about $200 in delayed interest for not making the payoff by the 6-month deadline. She fixed it for me, but I felt like I had really dodged an expensive bullet just by dumb luck. They want you to screw up on these promos, because they make a fortune off you. I would go the extra mile with Saks and phone CS to determine how can you track the balance of your 12-month purchase and if you can designate a certain amount of your regular monthly payment to go towards it. Good luck and hope that helps!