Determining the locked or unlocked status of an Android device involves verifying whether it’s restricted to a specific mobile network carrier. An unlocked phone can accept SIM cards from any compatible carrier, offering greater flexibility. As an example, if a device purchased from Verizon accepts and functions with a T-Mobile SIM card, it is considered unlocked.
The importance of knowing a device’s lock status lies in maximizing its utility and resale value. An unlocked phone offers the freedom to switch carriers to take advantage of better rates or coverage, especially when traveling internationally. Historically, phones were often locked to specific carriers to recoup subsidies on the device cost, but regulatory changes and consumer demand have increased the availability and desirability of unlocked devices.