Buying any kind of product in the store, everyone is already accustomed to the fact that the packaging of the goods must have a barcode, which is a vertical stripes and numbers under them.
Look at the numbers in the barcode. They contain information about the product and the manufacturer. The most common encoding methods for such information are the 13-bit European EAN-13 barcode and the UPC compatible code (also 13-bit), which is used in the United States and Canada.
Pay attention to the first three digits of the barcode, they indicate the country of manufacture of the product. For example, Russia corresponds to the code 460, Ukraine - 482, Bulgaria - 380, etc. A more complete list of the correspondence between the code numbers and the producing countries can be found on the Internet - on the sites dedicated to this issue.
The next four or five digits of the barcode contain information about the manufacturer. But this data is quite difficult for an ordinary buyer to decipher, since there is practically no such information on the Internet. This information is usually used by firms that carry out bulk purchases.
The next five digits of the barcode give the characteristics of the product: name, its consumer properties, size and weight, ingredients, color. As in the previous case, these data are more often used by large wholesalers rather than retail buyers.
Pay attention to the last digit in the barcode. This is a check digit that is used to check the accuracy of the barcode reading by the scanner. The last digit is used to determine the authenticity of the product
Determine if the item you purchased is counterfeit using the barcode.
Add up all the numbers in even places in the code, multiply the resulting amount by 3. Add up all the numbers in the odd places in the code, excluding the last check digit. Add the sum obtained with the product obtained by multiplying by 3. Discard the tens from the resulting number. Subtract the resulting number from 10. If it matches the check digit of the barcode, the product is genuine, otherwise you have a fake.