A serial number identifies one specific unit; an IMEI identifies a phone or other cellular device on mobile networks. Entering either on the manufacturer's website or app usually tells you the model and the warranty status the brand has on record. That is worth doing as soon as you buy, and again before any claim. But a successful check only proves that the number exists. It does not prove that the item in your hand is genuine, new or covered in your country. For the full routine on spotting fakes, see our guide to original accessories; this guide is about finding, checking and reading the numbers.
Serial number, IMEI and model number
| Identifier | What it identifies | Where to find it | Which devices have it |
|---|---|---|---|
| Serial number | One individual unit | Box label, the device itself, the companion app or settings | Almost all electronics |
| IMEI | A device on mobile networks, as a 15-digit number | Settings, the box, or dial *#06# on a phone | Devices that connect to cellular networks; Wi-Fi-only devices have none |
| Model number | The product type | Box and device label | Every product; shared by all units of that model |
The IMEI definitions above come from GSMA, the mobile industry body, on its Device Check service. Wireless earbuds, Bluetooth headphones and most smartwatches without a SIM have a serial number but no IMEI.