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Routing Number Validator

DataDeveloperSecurity

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INPUT

Auto Process

OUTPUT

Client Side

Enter a routing number to validate

Federal Reserve District

Check Digit

Checksum Calculation

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Guide

Routing Number Validator

Instantly validate US bank ABA routing numbers using the official checksum algorithm. Enter any 9-digit routing number to check whether it is valid, identify the Federal Reserve district, and see a step-by-step breakdown of the checksum calculation.

How to Use

1. Enter or paste a 9-digit ABA routing number in the input field. Spaces and dashes are automatically stripped.

2. The tool instantly validates the number and shows whether it is valid or invalid, along with the Federal Reserve district and a detailed checksum breakdown.

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3. Click “Try an example” to load a sample routing number (021000021 — JPMorgan Chase, New York).

Features

ABA Checksum Validation – Uses the official weighted-sum algorithm to verify routing numbers
Federal Reserve District Lookup – Identifies which Federal Reserve bank issued the routing number
Step-by-Step Breakdown – Shows the full checksum calculation with weights, products, and final modulo result
Instant Results – Validates automatically as you type, no button click needed
Format Tolerant – Strips spaces and dashes automatically

 FAQ

What is an ABA routing number?

An ABA routing number is a 9-digit code assigned by the American Bankers Association to identify financial institutions in the United States. It is used for wire transfers, direct deposits, and check processing.
How does the ABA checksum algorithm work?

The algorithm multiplies each digit by a weight (3, 7, 1, repeating), sums the products, and checks if the total is divisible by 10. If the remainder is 0, the routing number is valid.
What do the first two digits of a routing number mean?

The first two digits identify the Federal Reserve district that processes the routing number. Values range from 00 (US Government) to 80, with ranges 01-48 for paper checks and 61-80 for electronic transactions.