The serial number can be found near the barcode sticker on the packaging. It’s easy to identify because the model number is typically in the center of the serial number. If you are looking directly at your product, serial numbers are typically located on the top of our radios, however with amps, the number is located on the bottom. For speakers-- not all speakers have serial numbers on the products themselves. Again, a serial number is not a requirement to fulfill a warranty claim.