This service has been discontinued. The below information is displayed for historic purposes only.

We offer a free basic API. You can perform 100 free lookups per month. After that, the cost is $0.001 per lookup ($1.00 for 1,000 lookups).

To use the API, you need to first sign up for an account.

Once you have signed up, you will be given a secret key which is required in order to use the service.

To make an API call, choose whether you want a PHP serialized array or JSON encoded text, and provide a query. For example:
PHP: http://svc.webservius.com/v1/CorbanWork/aba_lookup/php/YOUR_QUERY?wsvKey=YOUR_SECRET_KEY
JSON: http://svc.webservius.com/v1/CorbanWork/aba_lookup/json/YOUR_QUERY?wsvKey=YOUR_SECRET_KEY

If the ABA number is found, you will get an array that looks like this:

Array
(
    [query] => 121202211
    [output] => php
    [result] => Array
        (
            [routing_number] => 121202211
            [office_code] => O
            [servicing_frb_number] => 121000374
            [record_type_code] => 1
            [change_date] => 080905
            [new_routing_number] => 000000000
            [customer_name] => CHARLES SCHWAB BANK NA
            [address] => 5190 NEIL ROAD  SUITE 300
            [city] => RENO
            [state_code] => NV
            [zipcode] => 89502-0000
            [telephone] => 888-403-9000
            [institution_status_code] => 1
            [data_view_code] => 1
        )

)

If the ABA number is not found, you will get an array that looks like this:

Array
(
    [query] => 12120221
    [output] => php
    [error] => Array
        (
            [number] => 404
            [message] => ABA number was not found in our database.
        )

)

You can search for bank names or ABA numbers. Full and partial searches are permitted.