I have tried to register for text message banking through the online banking site, but I never receive the activation code.

You may try re-sending the code to your phone through your online banking account. Go to the same page where you went to register the phone and click the link to have the code sent to your phone again. If that doesn’t work, please check with your carrier to verify that your phone and plan are enabled to send and receive both SMS and MMS messages. Also confirm with your carrier that your phone and plan are enabled to receive messages from short codes. Some carriers will block these, either at your request or based on your plan. First Internet Bank text message banking notices, including the activation code, will be sent from a short code (454545) rather than a 10-digit phone number.