While inserted, the UnlockMySIM sticker allows you to use your iPhone on any compatible network in the world, but it doesn't remove additional security measures such as private passwords, Touch ID, iCloud Activation Lock, Find My Phone or iPhones blacklisted due to loss, theft or non-payment.
These personal additional security measures can only be removed by the owner of the iPhone or Apple.
If you are unsure if your phone has been reported due to loss, theft or unpaid bill, use doctorSIM's Blacklist Check to remove all doubt.