It is important to remember that Fender serial numbers are NOT conclusively chronological. Back in the day, Fender made their serial number plates in big batches and the assembler simply grabbed a decal or more from the crate and slapped it on the guitar. To get as close as possible to determining the age of your Fender, make sure to check all dates on both body, neck and pots.
The locations of the serial numbers and dates change from model to model and in some cases they have simply been omitted.
For example, let’s take a Stratocaster with the serial number 279515 and the code 22384109B.
Starting with the letter B, this is the same neck width code Fender has been using since 1962.
From the production of the first solidbody Fender guitars and until 1976, Fender tagged a production date at the butt of the detachable neck of their guitars.
Only about half the guitars still carry any intelligible information here.
1972: A new eight-digit neck stamp was introduced colored either green or red. From 1972 to around March 1973, this new system was used simultaneously with the previous “XX MMM-YY W”.
Again, either stamp can occur on instruments from this era.
Sometimes a date is stamped or hand-written on the butt of the neck.
Vintage reissue instruments have the date on the butt end of the neck like the originals.
The Fender serial number decoder currently supports all documented MIA, MIJ, MIM, MIK and MII formats with the exception of Custom Shop, Relic and Reissue instruments.