---
title: "CUSIP"
description: "A CUSIP is a nine-character identifier for securities issued in the United States and Canada; it forms the middle nine characters of a US ISIN."
canonical: https://fundfactsapi.com/glossary/cusip
published: 2026-09-04
updated: 2026-09-04
publisher: FundFacts API
---

# CUSIP (CUSIP number, Committee on Uniform Securities Identification Procedures)

> A CUSIP is a nine-character identifier for securities issued in the United States and Canada; it forms the middle nine characters of a US ISIN.

## Definition

A **CUSIP** is a nine-character alphanumeric code that identifies securities in the United States and Canada. The first six characters identify the issuer, the next two the specific issue (a share class, bond or fund), and the ninth is a check digit. The system is operated by CUSIP Global Services on behalf of the American Bankers Association and takes its name from the Committee on Uniform Securities Identification Procedures.

A US ISIN is built directly from the CUSIP: the prefix `US`, the nine CUSIP characters, then an ISIN check digit. The same relationship holds for [SEDOL](https://fundfactsapi.com/glossary/sedol) inside UK and Irish ISINs.

## Why it matters

US mutual funds and US-listed ETFs are identified by CUSIP in brokerage systems and regulatory filings, while European systems, UCITS documents and most fund APIs work with [ISINs](https://fundfactsapi.com/glossary/isin). Anyone building for both markets needs to convert one into the other, and the conversion is deterministic in one direction only: a CUSIP can be turned into a US ISIN by adding the prefix and computing the check digit, but an ISIN from another country has no CUSIP.

## In the API

FundFacts API is keyed by ISIN, so a CUSIP must be converted before calling `GET /api/v1/funds/{isin}`. The response echoes the ISIN at top level; no separate CUSIP field is returned. Example values:

```json
{
  "isin": "IE00B4L5Y983",
  "name": "iShares Core MSCI World UCITS ETF USD (Acc)",
  "data": { "securityType": "ETF" }
}
```

## Common pitfalls

CUSIPs are licensed identifiers, so check redistribution terms before storing or displaying them. Ticker symbols are not CUSIPs and are not unique across exchanges; see [ticker](https://fundfactsapi.com/glossary/ticker). Coverage of US-domiciled funds by European data sources is typically thinner than for UCITS funds.

## About FundFacts API

FundFacts turns any fund or ETF ISIN into one dated factsheet (fees and KID costs, the 1–7 risk indicator, holdings, sector and country exposure, returns) read from the fund house's own documents: as a client-ready PDF under your firm's name for advisers and wealth managers, as JSON through its API for developers, or inside ChatGPT and Claude through its MCP server.

FundFacts works inside ChatGPT and Claude as a connector (a remote MCP server): ask about any fund or ETF by ISIN, ticker or name and the assistant answers from FundFacts' dated figures, fees, risk, holdings, exposure and returns, with fund cards, side-by-side comparisons, holdings overlap and portfolio look-through.

- Free API key, no card: https://fundfactsapi.com/signup
- Documentation: https://fundfactsapi.com/docs (OpenAPI: https://fundfactsapi.com/openapi.json)
- MCP server: https://fundfactsapi.com/api/mcp (set-up for every client: https://fundfactsapi.com/mcp-server)
- Pricing: https://fundfactsapi.com/pricing
- Site index for AI assistants: https://fundfactsapi.com/llms.txt
- Informational data, not investment advice.