Check securities identifier digits.
Initialising algorithm engine for CUSIP Check Digit Calculator...
How CUSIP Check Digit Calculator Works?
The CUSIP Check Digit Calculator works by converting the 8 CUSIP characters to values, doubling every second value, summing the digits of each result, and taking the complement to 10.
- 1Convert digits to 0–9, letters to 10–35, and * @ # to 36, 37, 38.
- 2Double the values in positions 2, 4, 6, and 8.
- 3Add the 2 digits of each value (for example 34 → 3 + 4 = 7).
- 4Sum the results to get S.
- 5Append (10 − (S mod 10)) mod 10 as the 9th character.
CUSIP Check Digit Calculator Formula
The CUSIP formula is Check = (10 − (Σ digitsum(vᵢ × wᵢ) mod 10)) mod 10, with wᵢ = 1, 2, 1, 2…
S = Σ (⌊vᵢwᵢ / 10⌋ + (vᵢwᵢ mod 10)), wᵢ = 1 for odd i, 2 for even i Check = (10 − (S mod 10)) mod 10 (CUSIP)
vᵢis the character value.wᵢis 1 or 2 by position from the left.
0 → 0 → digit sum 0 3 → 3 × 2 = 6 → digit sum 6 7 → 7 → digit sum 7 8 → 8 × 2 = 16 → digit sum 7 3 → 3 → digit sum 3 3 → 3 × 2 = 6 → digit sum 6 1 → 1 → digit sum 1 0 → 0 × 2 = 0 → digit sum 0 S = 30 Check = (10 − (30 mod 10)) mod 10 = 0 CUSIP = 037833100
CUSIP Check Digit Calculator Conversion Table
The CUSIP conversion table lists issuers with their 6-character issuer code, issue code, and check digit.
| Issuer | Issuer code | Issue | Check | CUSIP |
|---|---|---|---|---|
| Apple Inc. | 037833 | 10 | 0 | 037833100 |
| Microsoft | 594918 | 10 | 4 | 594918104 |
| Cisco Systems | 17275R | 10 | 2 | 17275R102 |
| Google (Class A) | 38259P | 50 | 8 | 38259P508 |
| Sample with @ | 12345@ | 10 | 7 | 12345@107 |
| Sample with # | AB1234 | #9 | 9 | AB1234#99 |
What is CUSIP Check Digit Calculator?
A CUSIP Check Digit Calculator is a tool that computes the 9th character of a Committee on Uniform Securities Identification Procedures (CUSIP) number. CUSIP Global Services assigns CUSIPs to US and Canadian securities.
The CUSIP has 3 parts: a 6-character issuer code, a 2-character issue number, and the check digit. The same 9 characters appear inside US ISINs.
What are the uses of CUSIP Check Digit Calculator?
There are 3 main uses of the CUSIP Check Digit Calculator, including trade settlement, ISIN creation, and security master checks.
- Trade settlement: Back offices validate CUSIPs on trade confirmations.
- ISIN creation: Data teams build US ISINs from CUSIPs.
- Security master checks: Operations teams find corrupted identifiers.