Regardless if you want to apply for an L-1A, L-1B, or blanket L visa, the application process entails a complicated one. The petitioner will have to submit the required documents to make sure that they establish and prove the relationship between the U.S. company and the company located abroad.
Also, based and depending on which country an employee is coming from, the L-1 visa will be approved for varying lengths of time. For L-1B visas, the time available is a maximum of five years, and for L-1A visas, the time available is slightly longer which is for a maximum of seven years, and an extension is even allowed.