Routing Number Lookup API

About the Routing Number Lookup API

A routing number validation API for ACH payment forms. Pass any nine-digit US routing number to run a routing number check against its mod-10 checksum and look up the bank name in a routing number database updated daily. The service categorizes the prefix as primary, thrift, electronic, or government, and identifies the Federal Reserve district. Paid plans add the registered street address, city and postal codes, office codes, and updated routing numbers for merged institutions.

What people use it for

Direct Deposit Setup

When onboarding new hires, payroll systems validate the entered routing number and auto-fill the financial institution name before issuing paychecks.

ACH Transfer Verification

To prevent transfer rejections, payment processors test mod-10 checksums and confirm the receiving bank matches customer paperwork before scheduling debits.

Accounting Vendor Onboarding

Procurement teams verify supplier banking details during vendor registration to catch typos and detect obsolete routing numbers before sending disbursements.

Merchant Account Enrollment

Flag invalid or non-standard bank routing numbers during merchant signup workflows to block fraudulent accounts and reduce settlement errors.

Ways to call it

One endpoint, many ways in — REST with JSON, XML, YAML and CSV, plus GraphQL and an MCP interface for AI agents.

JSON

Default REST response

XML

Markup format

YAML

Human-readable

CSV

Tabular export

Beta

GraphQL

Query language

New

MCP

For AI agents

Request parameters — GET /v1/routinglookup

Sent in the query string. Premium parameters are accepted on every plan but only take effect on plans that include them. Anything not listed here is dropped rather than passed through.

Required

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curl "https://api.apiverve.com/v1/routinglookup?routing=121000358" \
  -H "x-api-key: YOUR_API_KEY"

Authentication

Send your key in the x-api-key header. That is the only auth step — no token exchange, and no per-endpoint scope to configure.

Response — GET /v1/routinglookup

Every APIVerve endpoint returns the same three top-level keys, so one response handler covers your whole integration: status, error and data. Only data changes shape.

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{
  "status": "ok",
  "error": null,
  "data": {
    "routing_number": "121000358",
    "office_code": "O",
    "record_type_code": "1",
    "new_routing_number": "000000000",
    "bank": "BANK OF AMERICA, N.A.",
    "address": "8001 VILLA PARK DRIVE",
    "city": "HENRICO",
    "state": "VA",
    "zip": "23228",
    "zip_extension": "0000",
    "country": "US",
    "federal_reserve_district": "San Francisco",
    "federal_reserve_states": [
      "AK",
      "AS",
      "AZ",
      "CA",
      "GU",
      "HI",
      "ID",
      "MP",
      "NV",
      "OR",
      "UT",
      "WA"
    ],
    "address_in_district": false,
    "states_served": [
      "CA"
    ],
    "routing_type": "primary",
    "is_valid_checksum": true,
    "routing_analysis": {
      "is_head_office": true,
      "is_branch": false,
      "is_federal_reserve_bank": false,
      "is_active": true,
      "replaced_by": null
    }
  }
}

Response fields

Paths are relative to data. Premium fields are absent rather than zeroed on plans that do not include them, so check for presence instead of comparing to 0.

Response headers

Every response carries your balance, so your own code always knows where it stands without polling anything. All four are exposed to browsers through CORS.

Errors

Read the HTTP status first, then error for the specific reason. The body names the parameter that has to change.

What a call costs — 10 credits per call

Credits are shared across every APIVerve API — one balance, one key, one bill. Failed requests never count against it, so a rejected input costs nothing.

Calls are what the credits buy at this API's rate — spend them here, on any of the other APIs, or across both. Nothing is reserved per endpoint.

Zero-code embed — one snippet, no backend

Drop an interactive Routing Number Lookup form onto any page. The widget calls the API for you, so no key ever appears in your markup and there is nothing to deploy.

Changelog — Routing Number Lookup API

Every change to this endpoint, newest first. Breaking changes ship as a new version and the previous one keeps serving — response fields are added, never removed or retyped in place, so an integration written against v1 keeps working.

Currently v1Data refreshed daily