Access codes can come in different forms. Some are a physical card stock that is sent through the mail and others are emails that are delivered to the email address you use when placing the order. Below are some of the common ones and an example of what they look like.
Pearson MyLab Access codes
If you purchase a bundle, the access code will be packaged with the book. If you purchase a standalone access code, the access code will be emailed to you.
Generally, Pearson Access Codes last for 1 year and can be re-used for retaking the same course, or a new course that utilizes the same book. For example, AC1060, 1160, and 1260 all use the same book, so the Access Code can be re-used for each course. To re-use an access code, log back into the same Pearson Account that you already created when you first activated the code and register for the new course. It should allow you to register without asking for a new Access Code.
Cengage (Coursemate / MindTap)
These are sent either through the mail or through email. If you purchase a bundle, the access code will be packaged with the book. If you purchase a standalone access code, it will be emailed to the email address you use on the order. The access code that is packaged with the book looks like this.
Generally, Cengage Access Codes last for 6 months and can be re-used for retaking the same course. To re-use an access code, log back into the same Cengage Account that you already created when you first activated the code and register for the new course. It should allow you to register without asking for a new Access Code. If it does ask for a new Access Code, you may need to contact Cengage support.
McGraw Hill (LearnSmart Connect)
These are sent through the mail or via email, depending on how you order it. If you purchase a bundle, the access code will be packaged with the book. If you purchase a standalone access code, it will be delivered via email.
TestOut
This access code is delivered via email. The email looks like the one below.