IMEI is a unique, non-repeating number assigned to each cellular subscriber device: phone, modem, etc. By it, you can find out a number of data about the device, and if it was released before 2003, then the country of origin.
First, find out the IMEI number itself. To do this, find it on the sticker under the battery (if it is removable), directly on the case (near the modem), on the packing box, in the instructions. Also determine this number programmatically by going to the number input mode (for a device without a keyboard) or exiting all menus (for a device with a keyboard) and typing the USSD command * # 06 #. The numbers determined by all these methods must match, otherwise there is a possibility that you have a stolen device.
The IMEI number is fifteen digits long. If the device was released before January 1, 2003, find two among them: the seventh and the eighth. This is the so-called FAC - Final assembly code, that is, the code of the country in which the final assembly of the phone was made. It is not possible to find out by the IMEI the countries in which individual parts of the device are made, including the main board. It is also impossible to find out by this number and for which country of operation the mobile phone or modem is intended. If the device was released after January 1, 2003 inclusive, it is impossible to find out the country of origin by IMEI at all. In this case, the six digits from the third to the eighth are the type identifier that was previously occupied by the first through sixth digits. There is no information about the country of origin in it, so if a question like "what does FAC 03 means" is asked in forums, it makes no sense to wait for the correct answer.
If the device was released before 2003, it remains for these two numbers to determine the country of origin of the device. Please note that FAC has nothing to do with the country codes used in barcodes, especially since in the first case the codes are not always two-digit, and in the second they are always. Therefore, sites that allow you to determine the country of origin by the first digits of the barcode will not help. The most common codes are: 19, 40 - Great Britain, 07, 08, 10, 70 - Finland, 20 - Germany, 80 - China, 67 - USA, 30 - South Korea. In other countries, including Hungary, until 2003, mobile devices were hardly produced. If the device was released in 2003 or later, determine its country of origin by the inscriptions on the sticker under the battery, housing, packing box, instructions, etc.