CUSIP Identifiers Are Not Case Sensitive

Summary

The document answers a narrow question about whether CUSIP identifiers distinguish between uppercase and lowercase letters. It states that CUSIPs are not case sensitive and that letters in the identifier are written in uppercase. This is a practical point for people handling security reference data, such as when matching identifiers across files or systems.

The answer also gives brief historical context, noting that the identifier was developed by the American Bankers Association in 1967 and that its specification has changed little. It says letters are used in some parts of the scheme and relates their use mainly to debt securities and international issues. No validation procedure, character-by-character specification, or discussion of identifier variants is included, so the note provides a basic handling rule rather than a complete reference guide.

Key ideas

• CUSIP identifiers are not case sensitive.
• Letters in a CUSIP are conventionally written in uppercase.
• The identifier was developed by the American Bankers Association in 1967.
• The document associates letter usage mainly with debt securities and international issues.

Tags

# Are CUSIP case sensitive


# Are CUSIP case sensitive












Are CUSIP identifiers case sensitive like RIC number are?

## Answer by Richard at NorgateData (score 4)

https://quant.stackexchange.com/a/37124

CUSIPs are not case sensitive.

Any letters within a CUSIP are upper case.

The CUSIP identifier was developed in 1967 by ABA and has not changed significantly.

The specification for CUSIP is detailed here: https://www.cusip.com/pdf/CUSIP_Intro_03.14.11.pdf This provides some further detail about how letters (instead of digits) are used, and mainly relate to debt securities and international issues.

Shown in full with attribution under the source's licence. Licence: CC BY-SA 4.0 (Stack Exchange)

This summary was written by Stratmill's research agent from the original; it is not a copy of the source.