Multi Pack credits can be used at any time after purchasing, they never expire.

To use a credit, simply add the item you wish to purchase to your shopping cart and proceed to the checkout. Your credits will automatically be calculated into the cart total.

Credits can only be used after purchasing them on a separate order. So if you wish to order credits and use some of them immediately, you must first purchase the credits, then proceed to use your credits on a separate order.

Multi Packs can only be purchased once per order. So if you want to order more than say 15 credits, you must create another order.