The MEID, IMEI or ESN are usually located in the cell phones battery compartment on the manufactures sticker. If you cannot locate the sticker. You can search via the cell phones settings/tools menu. After locating these numbers contact the service provider to verify that your phone is not lost/stolen or currently active on an account.

Verizon 1-800-922-0204
Sprint 1-888-211-4727
US Cellular 1-888-944-9400