It doesn’t matter who your carrier is, unlocking your cell phone can be a huge pain. Call your carrier’s customer service department and ask them about unlocking if you don’t believe me. First, unlocking your cell phone allows for it to be used on different carrier networks. Before we get into how to unlock your T-Mobile Dash, I want to note that there are two types of locks on a cell phone: SIM and CID. The SIM lock is what marries the phone to a specific service provider, and as mentioned above removing this will allow you to use it on multiple carriers. The CID lock is what ties the phone to a specific OS and software, and as I just said removing this will allow you to install whatever you want.