Airtel Free SMS Trick 0 Trick 4:40 PM A+ A- Print Email 1. First of all activate the free SMS on your Airtel & than you will get 400 A2A free SMS. Now deactivate this service after 7 days & than again restart next day. You get 1200 free SMS A2A. 2. Message Setting -> Text Message -> Profile Setting & than change your Message Centre Number to +9810051905. works on Few Airtel numbers only. Enjoy free SMS.... Like it ? Share it.