The account last associated with the device must be in good standing. In order to check to see if the account is in good standing, you must have the account # or the full name of the account holder last associated with the device.
Unlocking policy here: https://www.sprint.com/legal/unlocking_policy.html
I am a former Sprint customer or was never a Sprint customer but have purchased a Sprint device from a third party other than Sprint. Can I have the device unlocked or receive the MSL code?
- For individual owners who can provide the account number or full account name last associated with the device, Sprint may be able to unlock the device or provide the applicable MSL Code respectively, provided the device is eligible under the applicable unlock policy. If a device is not eligible for any reason under the respective applicable policy, a non-Sprint customer requestor may be required to work with the original purchaser and/or the person from whom the requestor purchased the device to ensure any financial or device eligibility criteria are met.
Once that is verified you can request the domestic SIM unlock. That will also unlock it internationally.
If you have either the full name or the account number of the last associated account with your phone you can simple follow the below steps:
If you are a previous sprint customer,
Request a domestic SIM unlock
If you do not have the name or account number, you may be able to sweet talk someone at Sprint to give you one or the other.