Thanks for writing us about this. It depends on which discount you're hoping to use. Usually discounts on a specific product have an expiration date. For example, the deals of the day are on sale for one day only (or three days on the weekend).
Other discounts, like our Buy 2, Get the 3rd Free or Buy 1 Ebook, Get 1 Free, do not expire.
If you have questions about a specific discount code, let us know.
Have a great day!