You need 7 if you are Emerald Aisle and 6 if you are Executive Aisle. I love the reward credits. I used 2 free rewards last year and you can combine them. You can not use them with a coupon, however. I had 2 free days and used them both at one time and it took $45 off of my bill. I presently have 1 free day and 4 rewards, so am saving until I get a couple of days to use. They do, however, expire. The ones earned last year expire Dec. 31, 2005 and the ones I've earned already this year expire Dec. 31, 2006. I'm saving my free days to apply to a minivan rental that I need for September. Last year they ran a special and all rewards earned during the spring were doubled, hope they do it again since I have a 16 day rental for May and a 9 day rental for September.