Library numbers are on the back of your Wildcat ID card and begins with the numbers 202. If you don't have a Wildcat ID card, Library ID numbers can be found in your Portal in the Account Center. Go to the My Profile tab, and look for the field that says Library ID #. The number should begin with 20200.
For Interlibrary Loan Services, the online form fields have been edited to NOT require the library barcode number.