Some institutions have policies that credits expire after a certain number of years if you don't continue your education towards a degree at their institution. Others have no expiration date at all, particularly if the credits are transferred to another institution.
To find out if your credits will expire:
* Check with the institution that granted the credits: This is the most important step. Look for information on their website, usually in their admissions or registrar's office sections. You may need to contact them directly.
* Check the transfer policies of the institution you plan to transfer the credits to: Even if your original institution doesn't have an expiration date, a new institution might have its own rules about accepting older credits.
In short, assume credits *might* expire unless you have definitive proof otherwise from the relevant institutions.