If you wish to transfer your domain name to another domain name company, there are some factors which can either delay or prohibit the transfer from happening.
All issues have a solution, but some issues may take some time to resolve.
Brief list of issues affecting domain name transfers
Domain is 60 days or older:
Domains must have existed for 60 days or longer. New domain registrations cannot be transferred until this time has passed.
The domain name must not have a Lock on it. You must contact the current domain name registration company for the domain name to have locks removed.
Domain Authorization Code:
For most types of domains, you require a specific Authorization Code for the domain name to authorize the transfer. The current domain name registration company can provide this to you, however it may also be obtained within their web-based interfaces online.
Valid Administrative Contact:
For most types of domains, you must have a valid and functional Administrative Contact email address to receive the transfer confirmation notification emails. It's a good idea to turn off your anti-SPAM email filters while the domain transfers in order to receive these emails. If this email address is invalid and no longer works, you will need to update it through your current domain name registration company.