Overview
A routing number validation API for ACH payment forms, payroll and payout onboarding. Send a nine-digit US routing number: input that fails the ABA mod-10 check digit is rejected with a 400 before any lookup, and a valid number returns the bank name from a routing number database that is refreshed on a weekly cycle. Each match includes the routing type (primary, thrift, electronic or government), the Federal Reserve district by name and number, and, for banks that publish a routing number list by state, the states the bank assigns the number to. Paid plans add the registered street address, city and ZIP code, office and record-type codes, and the successor routing number when a bank has retired one.
Live Test Routing Number Lookup API →
Endpoint
One host, one path per API. The block below shows this call in four languages; every one of them is the same HTTP request. Making requests covers the timeouts, retries and parameter rules that apply to all of them. The SDKs wrap the same call in a typed client.
curl "https://api.apiverve.com/v1/routinglookup?routing=121000358" \
-H "x-api-key: your_api_key_here"const res = await fetch('https://api.apiverve.com/v1/routinglookup?routing=121000358', {
headers: { 'x-api-key': 'your_api_key_here' },
});
if (!res.ok) throw new Error(`${res.status} ${await res.text()}`);
const { data } = await res.json();
console.log(data);import requests
res = requests.get(
"https://api.apiverve.com/v1/routinglookup?routing=121000358",
headers={"x-api-key": "your_api_key_here"},
timeout=15,
)
res.raise_for_status()
print(res.json()["data"])package main
import (
"fmt"
"io"
"net/http"
)
func main() {
req, _ := http.NewRequest("GET", "https://api.apiverve.com/v1/routinglookup?routing=121000358", nil)
req.Header.Set("x-api-key", "your_api_key_here")
res, err := http.DefaultClient.Do(req)
if err != nil {
panic(err)
}
defer res.Body.Close()
out, _ := io.ReadAll(res.Body)
fmt.Println(string(out))
}Replace your_api_key_here with the key from your dashboard. When the inputs arrive as a list rather than one at a time, batch requests run up to 200 of them through this same API in a single call.
Authentication
Send your key in the x-api-key header. That is the only auth step — there is no token exchange and no per-endpoint scope to configure. Authentication covers creating, rotating and revoking keys.
A 401 means the key is missing, invalid or expired. A 403 means the key is valid but not permitted here — blocked by a key restriction or an IP allow-list. Running out of credits is a 429.
Parameters
Sent in the query string. Premium parameters are accepted on every plan but only take effect on plans that include them.
| Parameter | Type | Description |
|---|---|---|
routingRequired | string | The routing number to lookup information about length 9–9 |
Response
Every API returns the same three top-level keys, so one response handler covers your whole integration: status, error and data. Only data changes shape. Response format covers the envelope, the other output formats and how premium fields are withheld.
{
"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_district_number": 12,
"federal_reserve_states": [
"AK",
"AS",
"AZ",
"CA",
"GU",
"HI",
"ID",
"MP",
"NV",
"OR",
"UT",
"WA"
],
"address_in_district": false,
"states_served": [
"CA"
],
"latitude": 37.621745,
"longitude": -77.48896,
"timezone": "America/New_York",
"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.
| Field | Type | Example | Description |
|---|---|---|---|
routing_number | string | "121000358" | The ABA routing number for the bank |
office_codePremium | string | "O" | Office code designating the main office or branch location |
record_type_codePremium | string | "1" | Record type code indicating transaction type classification |
new_routing_numberPremium | string | "000000000" | New routing number if the bank has been updated |
bank | string | "BANK OF AMERICA, N.A." | Name of the financial institution or bank |
addressPremium | string | "8001 VILLA PARK DRIVE" | Street address the bank registered with the Federal Reserve for this routing number; national banks often use one central office for numbers in many states |
cityPremium | string | "HENRICO" | City of the bank's registered address for this routing number |
state | string | "VA" | Two-letter state of the bank's registered address; can differ from where the routing number is used (see address_in_district) |
zipPremium | string | "23228" | Five-digit postal code of the bank's registered address |
zip_extensionPremium | string | "0000" | Four-digit ZIP code extension for more precise location |
country | string | "US" | Country code (ISO 3166-1 alpha-2 format) |
federal_reserve_district | string | "San Francisco" | Federal Reserve district (e.g. San Francisco) derived from the routing number's first two digits; null for government or traveler's-cheque prefixes |
federal_reserve_district_number | number | 12 | Federal Reserve district number (1 Boston to 12 San Francisco) from the routing number's first two digits, with thrift and electronic prefixes folded back to their district; null for government or traveler's-cheque prefixes |
federal_reserve_states | array | [AK, ...] | Two-letter codes of the states and territories in the routing number's Federal Reserve district, i.e. where the number is issued; null for government or traveler's-cheque prefixes |
address_in_district | boolean | false | False when the registered address is outside the routing number's Federal Reserve district, typically a national bank's central office; null when there is no district or state |
states_served | array | [CA] | States where the bank itself tells customers to use this number for checking, ACH and direct deposit, from the bank's published routing-number list; null when the bank publishes no by-state list or the number is not on it (e.g. a wire-only number) |
latitudePremium | number | 37.621745 | Latitude of the bank office: the centre of its ZIP code, or of its city when the ZIP is one a large bank uses only for its own mail; null when neither can be placed |
longitudePremium | number | -77.48896 | Longitude of the centre of the bank office's ZIP code; null whenever latitude is null |
timezone | string | "America/New_York" | IANA time zone of the bank office (e.g. America/Chicago), useful for cut-off times; null whenever latitude is null |
routing_type | string | "primary" | Routing category derived from the routing number prefix: primary, thrift, electronic, government, or travelers_cheque |
is_valid_checksum | boolean | true | Whether the routing number passes the ABA mod-10 checksum |
routing_analysisPremium | object | {...} | Plain-language interpretation of the FRB office and record-type codes: head office vs branch, whether it is a Federal Reserve Bank, active vs superseded, and the replacement routing number if the institution was reassigned |
is_head_officePremium | boolean | true | The routing number belongs to the institution's head office (office code O) |
is_branchPremium | boolean | false | The routing number belongs to a branch office (office code B) |
is_federal_reserve_bankPremium | boolean | false | The routing number belongs to a Federal Reserve Bank itself (record type 0) |
is_activePremium | boolean | true | The routing number is in use; false when it has been superseded (record type 2) |
replaced_byPremium | object | null | The routing number to use instead when this one has been superseded; null while it is active |
Errors
Read the HTTP status first, then error for the specific reason. The body names the parameter that has to change. Error handling covers the full status list and which of them are worth retrying.
| Status | Meaning | What to do |
|---|---|---|
400 | Input was rejected | Read error; it names the parameter. |
401 | Key missing or invalid | Check the header name and the key value. |
403 | Key valid, but not permitted | A key restriction or IP allow-list; see key scoping. |
429 | Rate limited, or out of credits | Read error to tell them apart; see rate limits. |
Use cases
- 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
- Reject mistyped routing numbers during merchant signup and show the bank name back to the applicant, so a wrong digit is caught before the first settlement instead of after a returned payment.
Other ways to use Routing Number Lookup
Set up Routing Number Lookup on APIVerve, or reach the same source a different way. Your APIVerve account and credits work on all of them — one key, one balance.
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