If you have a Cricket phone, it may have been programmed with a lock that prevents it from operating with other compatible wireless networks. Cricket will provide the unlock code upon request, provided Cricket has the unlock code or can reasonably obtain it from the manufacturer, and you have met the following unlocking requirements:
The device you want to unlock has been active for at least six (6) months of paid service.*
The device is designed for use on and is locked to Cricket's network.
The device has not been reported lost or stolen.
The device is not associated with a fraudulent account.
Recently I purchased a Used Cricket phone online, and the seller told me that I could unlock it with cricket customer support. I did it with my old cricket phone in the past so I don't worry about it. However, it seems the unlock policy has changed to "only the account owner of the device" can unlock the device regardless of the phone actually met the unlock requirements.
On Cricket's website/device-unlock-policy, it does not clarify what a non-cricket customer need to unlock the device but just to call or chat customer service. I think this is misleading that it is possible for a non-cricket customer to unlock the phone. Of cause, you can argue that you could always ask the owner for the account information assuming the seller or friend would share this info to you like your family. And even if they do, why don't they just unlock the device for you, why do they have to go through all the troubles, exposing the account info to let a non-cricket customer unlock the device?
On top of the unlock requirement. The customer has to remember the associated account information in order to unlock the device. So if the account owner of the phone no longer using cricket and forgot the account information, he is no different than a non-cricket customer.
So a non-cricket customer or previous cricket customer who does not have access to the associated account to the device isn't qualified to unlock the device even if the device met the requirement.