1. Manufacturer: The M in the iPhone serial number that starts with M usually stands for Manufacturer. It indicates that the device was built by a particular manufacturer. Apple outsources the production of its devices to different manufacturers in different countries.
2. Region: The M prefix on an iPhone serial number means the device was manufactured in China, often at a Foxconn factory. The same can be said of other devices that start with different letters.
3. iPhone Model: The M in the iPhone serial number that starts with M might also indicate the model of the iPhone. For example, the 2019 released iPhone 11 series have model numbers such as A2221 (China), A2111, A2223. In this instance this could point to something like ‘Model’.
4. Carrier Locked: The M in the iPhone serial number that starts with M may also indicate that the device is carrier-locked. This is typically true for iPhones that have been purchased from a carrier or network operator.
5. Refurbished Device: In some cases, the M in the iPhone serial number that starts with M might indicate that the device is refurbished. Refurbished iPhones are devices that have been returned to the manufacturer due to defects or faults.
