As of November 2015, there are three ways to complete SmarTrip registration, including by fax, mail and online. The fastest of the three ways is to register the account online.
As of 2015, to fax in a SmarTrip registration, a cardholder faxes a note with the card serial number, name for the account, address and email address to 202-962-1035. To complete registration by mail, travelers need to send the same information to SmarTrip Regional Customer Service Center, PO Box 220568, Chantilly, VA 20153.
To register the SmarTrip card online, travelers start by visiting WMAT.com. On the lower edge of the screen, click on SmarTrip Card that appears in blue. In the middle of the screen, the traveler sees a yellow percentage button. Next to the yellow percentage button, click on the SmarTrip Card Benefits button.
The new page displays a lot of text and in the third paragraph, travelers click on the words "register your SmarTrip Card online" to get to the form to fill out. The form includes things similar to the information needed to register the card by fax or mail. Once completed, the traveler clicks on the Register button. Travelers can expect the registration to take 24 hours before taking affect.