Serial numbers were initially stamped on the bridges, whether it was a (“Pat. Pend.”) Locktight/Saddle-Lock bridge, as on this L-1000 bass or F-100 Series I guitar, or a Dual-Fulcrum Vibrato (DFV), as seen on this F-100 Series II w/DFV. Somewhere during 1983 G&L started using neck plates with a stamped serial number. This early-1983 L-1000F is the oldest bass on this site with such a neck plate and this late-1983 Cavalier the earliest guitar. But a hard date cannot be provided. This early-1984 1st style SC-3 still has a stamped serial number on the DFV, as does this mid-1984 HG-2 on the Saddle-Lock bridge. The latter guitar also shows a common problem with stamped serial numbers, especially when using black powder-coating filling up the recesses often rendering the serial number undecipherable. For all stamped serial numbers, a B0##### format was used for basses, with B000500 associated with a normal production L-1000 being the lowest, whereas guitars used G0#####, again with G000500 being the lowest for a production model. Lower serial numbers were reserved for special instruments with the lowest found on gold plated DFVs of those 1st X-body Interceptors built in 1983 for the then G&L leadership team. For example, S/N G000002 was built for Leo Fender himself. However, not all instruments with stamped serial numbers start with these prefixes. Intended exceptions are the ‘BC’ prefix used for the Broadcaster, the complete absence of a prefix on the Commemoratives with their ‘### of 1000’ format for guitars and ‘### of 150’ for the basses, the ‘GF####’ format for the (3-bolt) George Fullerton Signature model, and finally the rather off 22 ASAT Classic ‘Daddy’s 22nd Anniversary’ guitars with ‘## of 22’ as their serial number. The more interesting exception to the rule are some guitar neck plates used around 1995 right until the mid-1997 neck attachment change discussed below. They show serial numbers between B052000 and B055000 which are in the correct numeric range for a guitar built in that era but have the incorrect ‘B’ prefix. The only example on this site of this “aberration” is this 1995 ASAT Custom w/maple fingerboard. Another exception is the existence of 3-bolt guitar plates with additional ‘A’ stamped underneath the serial number to disambiguate it from a duplicate, as seen on this 1993 Legacy. This error is even rarer; only 8 serial numbers with that format are found in the Registry of the Guitars by Leo (GbL) website.

When G&L introduced the L-5500 5-string bass in 1993, it not only used a neck plate with a 6-bolt attachment, it also reset the B00#### formatted serial number stamped on that plate. The lowest L-5500 S/N found in the GbL Registry is B000008 with late-1993 date stamps and the highest B001199 with October 1996 stamps. Hence, there is an overlap in range between these S/Ns and those used for early G&L basses. As an example, S/N B000978 is both registered as an L-1000 from June 1980 as well as an L-5500 from June 1996!

Guitars transitioned to a 4-bolt neck attachment around mid-1997 and, with the exception of the 4-bolt George Fullerton Signature which kept its stamped serial number on the neck plate, a serial number water slide decal was applied underneath the final finish on the back of the headstock. Initially, the format was CL#####, with ‘CL’ standing for Clarence Leonidas, the first names of Leo Fender. The ASAT Semi-Hollow w/Bigsby with S/N CL06992 is the oldest and this ASAT S-3 with S/N CLF08983 the youngest of 3 examples on this site with this transitional format. The lowest serial number registered on the GbL website currently is S/N CF01360 and CL60115 the highest, giving you an idea of the range. When 1999 came around, the format had already changed to CLF######, starting with CLF10000, now using all of Leo’s initials. This ASAT ‘Junior’ is the oldest example on this site with this format using the uncommon white font. Usually, a black font is used, as seen on this Korina Collection ASAT Classic Bluesboy, the youngest on this site with a decal. There is good evidence the first batch of water slide decals with serial numbers between CLF10000 and CLF11340 all have a white font. They were also used in early-2005 on a series of all mahogany guitars, including this Legacy HB. A white font definitely provides much better contrast and readability on mahogany, is can be judged by comparing it to the black font on this ASAT Classic ‘Blues Boy’ Mahogany from mid-2005. A Black ASAT ‘Super’ with S/N CLF10425 built for export to Germany in April 2010 might be (one of) the last with such a white decal.

For G&L basses, the story is much more complex and depending on the model. The intricacies associated with the L-5500 are discussed above. The 5-string L-1505 and L-2500 used the same 6-bolt neck plate with B00#### formatted serial number as the L-5500 when introduced in 1996. Similar to the guitars, in 1997 they switched over to ferrules and a CL##### serial number on the headstock. And yes, when the format changed to CLF###### for guitars, it changed for these basses too. On the other hand, the ASAT Bass (Semi-Hollow), SB-1, and SB-2 kept their B0##### formatted serial numbers on a 3-bolt neck plate for many more years, certainly up to 2005 and maybe even 2006! A late, unused bass neck plate with S/N B034587 is shown below. It seems the upper limit for these is around S/N B35000, with B034997 currently the highest unused serial number registered. The L-1500 and L-2000 followed the same timeline as the guitars, with this L-1500 Custom from April 1997 among the last before the transition. These basses experienced the same transitional period with CL##### formatted serial numbers followed by CLF###### serial number by 1999.

For many years, there was no guarantee serial numbers were used in order at G&L, maybe with the exception of the Commemoratives. Bridges and neck plates with a stamped serial number or water slide serial number decals were thrown in a bin which acted much like a hat in a lottery drawing: whatever got pulled out would be used. Of course to avoid overstocking, some awareness of Just-In-Time (JIT) ordering in batches was used but there was no true chronology. For instance, G&L has published this table with ranges for instruments between 1980 and 1992 but, as evidenced by crosschecking serial numbers on this site, the reliability is not high. This changed in 2011 around the time the Korina Collection was introduced. Executive VP Dave McLaren wanted something special on a G&L instrument. Something that would showcase the pride with which each one is built. He came up with the idea of replacing the water slide serial number decal with a little brushed aluminum plate containing the serial number and the phrase “MADE IN FULLERTON, CALIFORNIA, USA - The Birthplace of Bolt-on™”. These plates started with S/N CLF061000 and were still mounted on the back of the headstock, now underneath the tuning machines. And they were used in sequence, implying higher numbers correspond to instruments built later. In addition, every instrument came with a ”Custom Build Specifications” sheet listing all relevant parameters like materials, setup, PLEK number, etc. Two copies of this sheet would henceforth be included in the black, gold-lettered G&L envelop: in principle 1 for the dealer and 1 for the end user. Still, the problem of serial number duplication was not fully eradicated, at least not numerically, mainly due to surplus water slide decals still being used after 2011 on some prototypes. Although a water slide decal has 5 digits versus 6 on a brushed plate, this 2014 ASAT™Cat has S/N CLF61097 whereas there should be a brushed plate with S/N CLF061097 out there somewhere.

In September 2016, the brushed aluminum plate was discontinued on production models. This Fallout is from April 2016 and with S/N CLF076921 the highest on this site. The brushed aluminum plate was temporarily replaced by a water slide decal with serial numbers in the CLF078000 to at least the upper CLF079600 range, as seen on this ASAT Classic Bluesboy (Empress) and SB-2T both still from 2016. In February of 2017, things changed one more time. The new serial number got a CLFYYMM### format where ‘YY’ represents the last 2 digits of the year, ‘MM’ the month, and ‘###’ the sequence number, and is laser-etched into the back of headstock after which it is filled with walnut stain to create the contrast and improve readability. This ASAT Classic Bluesboy Semi-Hollow okoumé w/Port Orford cedar top is from March 2017 and has this change applied. Also note the header on the accompanying sheet was simplified to “SPECIFICATIONS” at the same time. These changes also seem to coincide with some retooling causing the famous birthmark to disappear. The 2018 Winter NAMM, held between January 25-28 in Anaheim, CA, saw the introduction of the G&L Custom Shop as the next evolution of the Custom Creations Department. Their instruments have serial numbers with a CSYYMM### format underneath a G&L Custom Shop logo, as seen on this 2019 Custom Shop ASAT RMC P-90/HB, akin to a Custom Creations logo. However, excluding the 3 prototypes built in 2019, serial numbers for the production run of the Custom Shop 40th Anniversary Espada and L-2000 have a CS2020### format, i.e. a 4-digit year and no month, with the Espada starting at CS2020051 and the L-2000 at CS2020111. All other 2020 G&L Custom Shop instruments have the usual CS20MM### format. Incidentally, the G&L Custom Shop still uses brushed aluminum plates for any instruments also having an opaque back of the headstock, beyond the matching front, notably those with a Metal Flake finish. A known example is S/N CLF077758, a (still unregistered) 2018 Blue Metal semi-hollow Doheny. At the same NAMM event, G&L also introduced the CLF Research line with the reissue of the early-1980s looking L-2000 with similar shape for headstock and control panel, even up to the color switch tips, but with 6-bolt neck attachment. As seen e.g. on this CLF Research Espada, they carry the standard CLFYYMM### serial number format with an extra engraved ”CLF Research” above ”Fullerton, California”. Likewise, the Fullerton Deluxe guitars and basses, a line of popular G&L models introduced on September 12, 2018 and January 23, 2019, respectively, with restricted options and colors, have “Fullerton Deluxe” etched underneath their serial number.