Bookstore codes, Inclusive Access codes and coupons are usually between 8-12 characters long, usually without dashes. If you ever have trouble using a code you bought from your bookstore, send an email to email@example.com with the code you were having trouble with along with a copy of the receipt for your purchase.
PLEASE NOTE: The only codes that can be entered into the coupon field at checkout are coupons, Inclusive Access codes and bookstore codes. If you are attempting to enter a Community Lookup Key (32 characters long with multiple dashes) on the checkout screen, you will receive an error "Sorry, that isn't a valid access or coupon code" and will be unable to complete registration.
Community lookup key format: XXXXXXXX-XXXX-XXXXXXXX-XXXXXXXXXXXX
If you've been invited to your community you wouldn't need to worry about using or having a community look key. After logging into your account, just go to the Join a Community page and follow the steps on the screen to join your community!