Identifiers and crosswalks

Every federal regulator maintains its own primary key for the institutions it supervises. The same bank shows up under different numbers in each source. This page is a reference for which identifier each regulator uses and what public crosswalks exist.

The four main identifiers

Identifier	Issued by	Covers	Format
RSSD ID	Federal Reserve	Every Fed-regulated entity (bank, branch, BHC, subsidiary, non-bank affiliate)	Integer, up to 10 digits
FDIC CERT	FDIC	Insured depository institutions	Integer
OCC ID	OCC	National banks, federal savings associations	Integer (charter #)
Branch UNINUM	FDIC	Individual bank branches	Integer

What crosswalks exist

The Federal Reserve’s NIC attribute extract is the primary public crosswalk:

ID_RSSD ↔ ID_FDIC_CERT — for institutions with both.
ID_RSSD ↔ ID_OCC — for institutions with both.
ID_RSSD_HD_OFF — links an entity to its top-tier holder (parent resolution).

That crosswalk is complete enough to join the Fed’s financial data to the FDIC’s Institutions.csv or the OCC’s national-bank list.

Where crosswalks fail

Branches. The Fed publishes a branch extract (keyed on RSSD-of-branch). The FDIC publishes the Summary of Deposits, keyed on UNINUM. There is no public UNINUM ↔ RSSD crosswalk. Matching must be done heuristically — by address, institution RSSD+branch-number, or fuzzy name matching — and will never be 100% clean.

Historical identifiers. Pre-1976 data uses older schemes that don’t fully map to current RSSDs. Most modern analysis starts at 1976 or later.

Non-bank subsidiaries. Some Fed-regulated non-bank affiliates have RSSDs but no FDIC or OCC counterpart — there is nothing to crosswalk to.

State charters. State regulators issue their own IDs; there is no centralized crosswalk to RSSD. The NIC extract records the state charter where available but coverage is uneven.

Practical implications

When building a join:

Start from RSSD. It is the broadest and most stable.
If your upstream key is FDIC CERT or OCC ID, join through the NIC attribute extract to get the RSSD, then use that.
For branch-level analysis, expect to lose ~5–15% of branches to address mismatch between NIC and Summary of Deposits.
Validate lifecycle. A bank that was merged mid-period will have its time series continue under the survivor’s RSSD — not under the non-survivor’s.

Quick lookups with the library

collect_filers_on_reporting_period() returns, for each filer, all four regulatory identifiers plus the primary ABA routing number when available. That panel is effectively a point-in-time crosswalk for the quarter in question — useful when you don’t want to pull the full NIC extract.