You need to verify a U.S. bank by routing number and return actionable details (institution name, address, phone, ACH status) so you can move money confidently. By the end of this guide, you’ll query a real finance endpoint on Zyla API Hub that returns bank information for a routing number and wire it into your app with a minimal amount of code.
What this API does and why it matters for finance integrations
The Routing Number Bank Lookup API provides bank metadata from a routing number: institution name, address, phone, branch type (e.g., main office), whether it’s active, and when it was last updated. It also validates routing numbers and confirms ACH support depending on the endpoint you choose. This is useful anywhere you must accept bank details safely: onboarding flows, payouts, vendor management, and accounting automations.
You make a simple GET request and receive normalized JSON with exactly the fields you need to decide if a routing number is valid and to display or log the bank’s profile for audit trails and customer support.
Getting started on Zyla API Hub
Open the API listing on Zyla API Hub and subscribe. Zyla provides one account, one API key, and one subscription model across more than 10,000 public APIs. For your first API, you can typically start with a 7-day trial or 50 requests—check the item page for current access options and pricing. After subscribing, you’ll receive an API key you can use with the Authorization header.
- Browse: https://zylalabs.com
- Subscribe on the listing: Start 7-day trial on Routing Number Bank Lookup API
- Use the header: Authorization: Bearer YOUR_API_KEY
Endpoints you will use
This API exposes two GET endpoints on Zyla API Hub. Use the one that best matches your task.
1) Get Bank Information
Method: GET
URL: https://zylalabs.com/api/331/routing-number-bank-lookup-api/266/get-bank-information
Description: Returns detailed information about a routing number including financial institution name, ACH routing number context, branch type, full address, contact phone, active status, and last update date.
Required query parameters:
- routingnumber (number): e.g., 121000245
- paymentType (string): ach
Example request (copy-paste):
curl -s -X GET "https://zylalabs.com/api/331/routing-number-bank-lookup-api/266/get-bank-information?routingnumber=121000245&paymentType=ach" \
-H "Authorization: Bearer YOUR_API_KEY"Example response:
{
"status": "success",
"data": {
"routingNumber": "121000245",
"paymentType": "ach",
"name": "Wells Fargo Bank, Na",
"addressFull": "255 2nd Ave South, Minneapolis, MN 55479",
"street": "255 2nd Ave South",
"city": "Minneapolis",
"state": "MN",
"zip": "55479",
"type": "Main Office",
"phone": "800-245-2426",
"active": true,
"lastUpdated": "2026-07-29"
}
}What you’ll actually use:
- data.routingNumber and data.paymentType: confirm you queried the intended number and ACH context.
- data.name, data.addressFull, data.phone: show bank details to the user or log for compliance.
- data.type and data.active: ensure it’s an active institution and understand the branch role.
- data.lastUpdated: record freshness; consider re-checking if this date is older than your risk threshold.
2) Bank Data
Method: GET
URL: https://zylalabs.com/api/331/routing-number-bank-lookup-api/1353/bank-data
Description: Retrieves information about a bank by routing number and validates whether the routing number is correct. Returns bank name, address, phone, and a validation message.
Required query parameters:
- number (number): e.g., 304082876
Example request:
Example response:
What you’ll actually use:
- message and success: quick validation signal for the routing number.
- data.bank, data.address, data.city, data.state, data.zip, data.phone: displayable institution details.
- data.date_of_revision and data.new_routing_number: track revisions and watch for updated routing numbers.
Which endpoint should you choose?
- Use Get Bank Information when you need ACH context and a richer object with explicit active status, branch type, and lastUpdated.
- Use Bank Data when you want a compact “valid” message with bank contact fields and revision details.
Authentication and request pattern
All calls are made to Zyla API Hub endpoints with a Bearer token:
- Header: Authorization: Bearer YOUR_API_KEY
- HTTP method: GET
- Query parameters: exactly as shown for each endpoint
Requests are subscription + quota based (not pay-per-call). For a new integration, plan around the initial allowance (typically a 7-day trial or 50 requests) and upgrade as needed on the API page.
Python example: validate a routing number and render bank info
The snippet below calls the Get Bank Information endpoint and prints the fields you’re likely to show in a UI or store in a ledger record.
import requests
API_KEY = "YOUR_API_KEY"
url = "https://zylalabs.com/api/331/routing-number-bank-lookup-api/266/get-bank-information"
params = {
"routingnumber": 121000245,
"paymentType": "ach"
}
headers = {
"Authorization": f"Bearer {API_KEY}"
}
resp = requests.get(url, params=params, headers=headers, timeout=15)
resp.raise_for_status()
payload = resp.json()
if payload.get("status") == "success" and "data" in payload:
data = payload["data"]
print("Bank:", data.get("name"))
print("Routing Number:", data.get("routingNumber"))
print("ACH Payment Type:", data.get("paymentType"))
print("Address:", data.get("addressFull"))
print("Phone:", data.get("phone"))
print("Branch Type:", data.get("type"))
print("Active:", data.get("active"))
print("Last Updated:", data.get("lastUpdated"))
else:
# Handle unexpected structure or validation failure
print("Lookup failed or returned unexpected format:", payload)Notes:
- The example uses the documented query parameters only: routingnumber and paymentType.
- Adjust timeout and add retry logic appropriate for your environment.
- Persist the lastUpdated field and re-validate on a cadence that matches your risk posture.
Practical implementation tips
- Validation flow: call Bank Data to quickly check if the number is valid and log date_of_revision; on success, optionally call Get Bank Information to enrich with active status and branch type before initiating ACH setup.
- User feedback: surface bank name and city to help users confirm they typed the right routing number without exposing account details.
- Error handling: treat any non-200 HTTP or a success=false response as validation failure and prompt for re-entry without leaking internal error messages.
- Caching: routing numbers don’t change frequently; you can cache successful lookups per routing number for a day or week. Always honor your own revalidation policy if you rely on lastUpdated or date_of_revision.
- Auditing: store the exact JSON you received (or selected fields: routingNumber, name, active, lastUpdated) alongside the time you performed the check.
End-to-end example flow for finance teams
- Onboard collects routing number from the customer.
- Call Bank Data to validate. If success is true, parse bank name and address for confirmation UI.
- Optionally call Get Bank Information to check active status and branch type if your ACH workflow requires it.
- Store the normalized bank object and the timestamp of validation in your customer record.
- Proceed with micro-deposits or ACH authorization knowing the routing number points to the expected institution.
Calling the API from an AI agent via MCP
You can also reach Zyla APIs from MCP-compatible tools. Point your client to the MCP endpoint and supply your Zyla API key to let the agent make the same GET calls shown above from within your development environment.
- Docs and endpoint: MCP
- API key: use the same key from your Zyla subscription.
- The agent should call the exact Hub URLs and pass Authorization: Bearer YOUR_API_KEY.
If you’re orchestrating a chain-of-thought workflow, constrain the agent to the two endpoints documented here to avoid unintended calls.
Operational considerations
- Idempotency: lookups are read-only; you can safely repeat a request if a network error occurs.
- Throttling: design with exponential backoff and simple client-side rate limits even if your current plan rarely hits limits.
- Monitoring: log routing numbers (masked as needed for privacy policies), response status, and timing to detect upstream issues early.
- Security: keep your API key in a server-side secret store. Do not expose it in client-side or mobile apps.
Reference: Endpoints summary
- GET https://zylalabs.com/api/331/routing-number-bank-lookup-api/266/get-bank-information
- Params: routingnumber=121000245, paymentType=ach
- Returns: name, addressFull, phone, active, type, lastUpdated, and more within data
- GET https://zylalabs.com/api/331/routing-number-bank-lookup-api/1353/bank-data
- Params: number=304082876
- Returns: success, message, and bank details in data
Where to subscribe and get your key
Subscribe on the Zyla API Hub listing to receive your API key, manage quotas, and access analytics. The first API typically offers a 7-day trial or 50 requests so you can ship your integration this week. For broader discovery, browse the catalog here: https://zylalabs.com.
FAQ
Q: Which endpoint should I use to check whether a routing number is valid?
A: Use the Bank Data endpoint. It returns success and a validation message, plus bank details.
Q: How do I confirm ACH support or see if the bank entry is active?
A: Use the Get Bank Information endpoint with paymentType=ach. It includes active status, branch type, and lastUpdated fields.
Q: What authentication does the API require?
A: Pass Authorization: Bearer YOUR_API_KEY in the request header to the Zyla API Hub URL.
Q: Can I cache results?
A: Yes, routing numbers change infrequently. Cache by routing number and re-validate on your own schedule using lastUpdated or date_of_revision as guides.
Q: Is there a free plan?
A: The model is subscription + quota, not pay-per-call. For your first API, you can typically start with a 7-day trial or 50 requests; check the API page for current access options and pricing.
Ready to implement routing number validation and bank lookup in minutes? Subscribe on the item page and start your 7-day trial: Routing Number Bank Lookup API.
