Contact Customer Service

Customer Service Center

The GSO Customer Service staff is here to help, and you can reach a live person at 800-322-5555 during business hours. For your convenience, you can log into your GSO account at any time to track a package, schedule a pickup, calculate rates, view transit times, and much more.

Hours of Operation

GSO Customer Service Center departments are staffed from 7:00 a.m. to 8:00 p.m. Monday through Friday and from 7:00 a.m. to 4:00 p.m. on Saturday. Customer Service staff are available only for emergency situations after hours and on Sundays and holidays.

Customer Service

Phone: 800-322-5555
Fax: 916-636-5101
Email: customerservice@gso.com

Sales

Phone: 800-322-5555 Extn 4
Email: sales@gso.com

Billing

Phone: 800-322-5555 Extn 6
Fax: 408-543-8301
Email: billing@gso.com

Corporate Address

GSO
7901 Stoneridge Drive
Suite 400
Pleasanton, CA 94588