Smartphones can be locked or unlocked. A carrier-locked smartphone is only meant for use with a specific wireless carrier. An unlocked smartphone can be used with any carrier with compatible bands.

Unlocked smartphones can either be carrier-unlocked or factory-unlocked. Swappa only allows factory-unlocked devices to be listed in the unlocked category. Devices that were originally purchased from, or locked to a specific carrier, must be listed under their original carrier.

• Carrier unlocked: Originally purchased from or locked to a single wireless carrier, but later unlocked by the carrier for use on other carrier networks.
• Factory unlocked: Often originally purchased directly from the manufacturer, and has never been locked to a specific carrier.
• Flex Device: US Reseller Flex Policy, also known as SIM OUT, allows retail stores to sell devices that have not yet been locked for use on a specific US cell carrier. However, these devices will lock to the first US carrier they connect to after inserting a compatible SIM card.

Network Compatibility: Not all unlocked devices are compatible with all carriers. For example, an unlocked smartphone intended for use with a US carrier may not work with an international carrier.

Unlocked Non-US: Swappa is a U.S.-based marketplace, but we do include a category for international factory unlocked devices, labeled as "Unlocked Non-US". Devices in this category might work in the U.S., but buyers are expected to confirm compatibility with their carrier prior to purchasing an "Unlocked Non-US" device.

Samsung U vs U1: Factory unlocked U1 Samsung devices should be listed in the unlocked section. Samsung carrier U devices must be listed in the original carrier section, even if sim unlocked or software flashed.

Google Pixel: Only factory unlocked Google edition Pixels should be listed in the unlocked section. Carrier Pixels must be listed in the original carrier section, even if sim locked, due to bootloader restrictions.

Learn more about carrier compatibility on the Swappa blog:

• Unlocked iPhone Carrier Compatibility Guide
• Android Phone Compatibility Guides