For the purposes of this help article, an inactive Sprint device is one that doesn't have active Sprint service. Deactivating your Sprint device is as simple as cancelling your Sprint account.
If you have one device on your Sprint account
Call the Sprint help desk (1-888-211-4727) and speak to an customer service representative to close out your account. You will lose your current mobile number.
If you have multiple devices on your Sprint account
If you want to deactivate all the Sprint devices under your account, just follow the above process for each device. If you only want to bring one single Sprint device that's currently on a shared Sprint plan: