Routing Number Lookup API + Mailchimp Integration

Why connect them

The Routing Number Lookup API in Mailchimp.

Mailchimp is the leading email marketing platform for businesses of all sizes. Integrating APIs with Mailchimp enables automated list cleaning, real-time subscriber enrichment, and data-driven segmentation. Send better emails to verified, enriched audiences.

What you can build

Workflows worth wiring.

Validate all new subscriber emails before adding them to your lists

Automatically tag subscribers based on their geolocation data

Clean your existing lists by identifying invalid or risky email addresses

Enrich subscriber profiles with timezone data for optimal send time optimization

Templates

Ready-made ideas.

New subscriber added to Mailchimp Fetch routing lookup for subscriber routing number → tag subscriber with bank and state

Bank Region Segmentation in Mailchimp

Tag Mailchimp subscribers by bank and state using routing number lookups for regional campaigns.

New subscriber added to Mailchimp Fetch routing lookup → tag subscriber with bank name for institution-specific email segments

Financial Institution Targeting in Mailchimp

Segment Mailchimp subscribers by their bank name from routing number data for targeted messaging.

Setup

Connect it in a few steps.

Set up with Zapier

1
Set the trigger. Create a Zap with Mailchimp as the trigger app and "New subscriber" as the event. Connect your account.
2
Add the API action. Add APIVerve as the action, select the Routing Number Lookup API, and map your trigger data to the request.
3
Send it back. Add a second Mailchimp action for "Add subscriber" and map the returned fields (like routing_number) into it.
4
Test & turn on. Test the Zap with real data to confirm the mapping, then turn it on.

Set up with Make

1
Add the trigger. Create a scenario and add a Mailchimp module set to "New subscriber". Authenticate your account.
2
Call the API. Add an HTTP module pointing at api.apiverve.com/v1/routinglookup with your x-api-key header. Pass the trigger's data as the input.
3
Parse & map. Add a JSON module to read the response, then a Mailchimp module for "Add subscriber". Map fields like data.routing_number into place.
4
Activate. Run once to confirm the mapping, then switch the scenario on and set its schedule.

Set up with n8n

1
Add the trigger node. Start a workflow with a Mailchimp trigger node for "New subscriber" and connect your credentials.
2
Add an HTTP Request node. Point it at api.apiverve.com/v1/routinglookup using Header Auth (x-api-key). Feed in the trigger data.
3
Map with expressions. Add a Mailchimp node for "Add subscriber" and reference the response with expressions such as {{ $json.data.routing_number }}.
4
Execute & activate. Execute manually to verify, then activate the workflow for production.

The payload

What Mailchimp receives.

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"

Routing Number Lookup API + Mailchimp