There are two different cards:
1) Corporate Card (you sign up through a company),
2) Brooks [Credit] Card (you need to apply for this store-branded credit card).
The first card, the corporate card, takes 15% off full-price purchases ANY TIME. About twice a year, there is a corporate sale which doubles the discount to 30%. This card's discount stacks with Brooks Buys (3 for $225 Shirts, $2 for $129 Pants, etc.) but not for any items on sale or clearance.