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Check My Guitar

Gibson guide

Gibson Custom Shop serial numbers

Custom Shop numbering records one digit of the year. That means the same serial pattern comes round every ten years, and the serial alone cannot separate the decades.

CS-prefix serials

A serial beginning CS is a Custom Shop instrument. The digit immediately after the prefix is the last digit of the year; the rest is a production sequence.

This is where the ambiguity comes in. CS40123 has a year digit of 4, which is equally consistent with 2004, 2014 and 2024. The serial cannot separate them, and any tool that presents one of those as the answer is guessing on your behalf.

Examples

  • CS40123 — 2004, 2014 or 2024
  • CS901234 — 2009, 2019 or 2029

Historic Collection reissue serials

Historic and reissue instruments are numbered with a single year digit followed by a four-digit sequence, usually written with a space after the first digit — 9 1234 rather than 91234. The same decade ambiguity applies.

The model designation, not the serial, is what tells you which reissue you are looking at. An R9 is a 1959 Les Paul reissue regardless of when it was built; the serial tells you the build year, and the two are routinely confused in listings.

Reissues and forgery

Custom Shop reissues are among the most frequently counterfeited instruments on the market, precisely because they are valuable and their numbering is thin. A plausible serial is a starting point and nothing more. For any significant purchase, the Certificate of Authenticity, the original paperwork and a physical inspection by someone who knows the model matter far more than the number.

Narrowing the decade

  1. Check the Certificate of Authenticity, which normally states the year outright.
  2. Read the potentiometer date codes through the control cavity — they place the electronics within a couple of years.
  3. Compare the case, case candy and hardware against documented examples from each candidate decade.
  4. Check the model specification against what the Custom Shop was building in each of those years.

Common questions

Why does my CS serial return more than one year?
Custom Shop serials record only the last digit of the year, so the same pattern repeats every decade. Returning every consistent year is the honest answer; the paperwork or the pot codes will separate them.
Does a Custom Shop serial confirm the instrument is genuine?
No. Custom Shop instruments are among the most frequently faked, and a counterfeit will normally carry a plausible-looking serial. Treat the number as one weak signal among many.

Last reviewed 29 July 2026. Spotted something wrong? Report a correction.