LinkedIn assigns unique identification numbers to each profile. You may need this ID number if you are working with LinkedIn's API for website integration. Because the ID number is part of the profile URL, you simply need to view the LinkedIn profile to determine the ID number.
Sign in to LinkedIn. Click on the "Profile" tab.
Click on "View My Profile" to view your LinkedIn profile. If you wanted to find someone else's LinkedIn ID, view the person's profile.
Examine the profile URL. The series of numbers following "id=" is your LinkedIn ID.