What are some free unused serial codes for The Sims 3

Actually, you can contact EA help line [(650) 628-1001], and theyll give you a free serial number as long as you have the disk. Youll need to verify with an email, though, so make sure you have sims 3 online account.

Source: I tried it with my late nite expansion and they gave me a free serial number. Remember they dont really lose money from issuing out free serial numbers, they lose money if they dont sell disks.