To take advantage of the offer, simply text "raincheck" to 888-222. You'll receive a link to a landing page asking for your name and zip code and after submitting the info, they'll send/text you a coupon for a free burrito in the new few days.
The promotion runs today, February 8, 2016, from 11 AM to 6 PM EST, with limited quantities on a first come, first serve basis. You can find additional details on their website here.
Image via Chipotle.
