If you are in your vehicle, push the blue OnStar button. Or you can call us toll free at 1.888.4.ONSTAR (1.888.466.7827). Advisors are available 24 hours a day, 7 days a week. Subscribers who are deaf, hard-of-hearing, or speech impaired may call our toll-free TTY number for assistance at 1.877.248.2080.