How do i contact dfas customer service? (800) 877-0996 Customer Service (Voice, TTY, ASCII and Spanish) – Allows callers to connect with Customer Service Learn more about our Customer Experience Team and how they are helping to improve your experience with DFAS.Why choose dsfederal? We work together to support our clients’ missions and improve the health and safety of the world. The DSFederal team is collaborative, innovative, and dedicated to ensuring positive mission outcomes for our clients. Our people are united by one goal – to make the world a better place.How do i dial us toll free numbers on disa? Overseas DSN Users: Overseas DSN users can now dial US toll-free numbers by simply dialing 94 + the 10-digit toll-free number. For more information, check out this DISA tutorial.What are the toll free numbers for the federal relay? Toll-free and toll access numbers for the Federal Relay are: (800) 877-8339 TTY / ASCII (American Standard Code for Information Interchange) – Allows TTY users to type their conversation (877) 877-6280 VCO (Voice Carry Over) – Allows users to voice their conversation