Most guitar manufacturers put a serial number on each instrument they produce. This number can be used to date a guitar and in some cases tell where it was made. Serial numbers tend to be stamped or written somewhere on the headstock or neck joint of the guitar. On some acoustic guitars, the serial number is on the inside of the sound hole. Serial numbers are often at least four digits long, and they sometimes include letters.
Search the area around the serial number for a date stamp. Not all guitar brands use date stamps, but if you find one, you have your answer.
Look for the brand name decal on the guitar's headstock. Each guitar brand uses a different set of serial numbers, so you need to identify your guitar before you attempt to use the serial number to learn when it was made.
Determine the type of guitar (such as Gibson Les Paul or SG, Fender Stratocaster or Telecaster) if possible. This can help when you are researching serial numbers. This information is often written on the headstock or truss rod cover. An online search of the brand name can help you do this.
Visit the manufacturer's website and look for serial number information. Many guitar makers have brand-specific serial number information on their web pages, usually in the "Support," "FAQ," or "Info" sections. Sometimes third-party websites also have solid information on guitar serial numbers.
Email the serial number to the manufacturer and ask for help. Attach a few high-quality pictures of the guitar to the email to assist the manufacturer.