T-Mobile headquarters sits at 12920 SE 38th Street in Bellevue, Washington — but since the 2020 Sprint merger the company has officially run on two campuses, with a second headquarters on the former Sprint campus in Overland Park, Kansas. Below you will find everything you need to reach the carrier: the current corporate office address, the verified customer care numbers (611 or 1-800-937-8997), the mailing address that actually reaches T-Mobile Customer Relations, and the escalation steps that work when a billing or service dispute stalls.
| Headquarters | 12920 SE 38th Street, Bellevue, WA 98006, United States |
| Corporate office | T-Mobile US, Inc., 12920 SE 38th Street, Bellevue, WA 98006 (executive offices — no customer service or payments handled here) |
| Second headquarters | Former Sprint campus (Aspiria), Overland Park, Kansas — about 3,500 employees |
| Customer service phone number | 611 from a T-Mobile phone, or 1-800-937-8997 (daily, 4 AM–9 PM Pacific) |
| T-Mobile for Business | 1-833-800-0323 |
| 5G Home Internet technical support | 1-844-275-9310 |
T-Mobile Headquarters Location and Contact Information
T-Mobile US, Inc. lists 12920 SE 38th Street, Bellevue, Washington 98006 as its principal executive office in its most recent annual report (Form 10-K), filed with the SEC in February 2026. The campus occupies a cluster of office towers in the Factoria neighborhood of Bellevue, just east of Seattle, and was extensively remodeled after the Sprint merger into a single one-million-square-foot workplace for executives, network engineers, and marketing teams. The same filing gives the corporate switchboard as (425) 378-4000 — a number for investors and business contacts, not for account help.
What makes T-Mobile unusual is that the 10-K states plainly: “Our headquarters are located in Bellevue, Washington, and Overland Park, Kansas.” The Overland Park site is the former Sprint world headquarters, now called Aspiria, which T-Mobile designated as its secondary headquarters when the merger closed in April 2020. Neither campus is a customer-service location. You cannot walk into the Bellevue corporate office to pay a bill, swap a SIM, or dispute a charge — for anything account-related, use the phone numbers below, the T-Life app, or the T-Mobile store locator.
Phone Contacts
T-Mobile runs separate lines for sales, customer care, and technical support, and each has its own hours. These numbers are taken directly from the carrier’s official contact page:
- Customer care (existing customers): dial 611 from your T-Mobile phone, or 1-800-937-8997 — representatives available daily, 4 AM to 9 PM Pacific Time
- Consumer sales (new customers): 1-844-222-1938
- T-Mobile for Business: 1-833-800-0323
- 5G Home Internet sales: 1-833-983-3596
- 5G Home Internet technical support: 1-844-275-9310
- T-Mobile Fiber sales: 1-844-931-1830
- T-Mobile Fiber technical support: 1-844-783-4237
- International customer service (calling from abroad): 1-505-998-3793
- TTY: dial 711 to reach a relay agent
Customer Service and Support Channels
Phone is not the only way in, and for many tasks it is not the fastest. The T-Life app handles bill payments, plan changes, upgrades, and network troubleshooting around the clock, and it includes live agent chat from 4 AM until midnight Pacific — three hours longer than the phone lines stay open. Because chat conversations are tied to your logged-in account, they also leave a written record, which is useful if you later need to escalate.
On social media, T-Mobile answers public questions through its verified @TMobile accounts on X, Instagram, and Facebook, though agents will move you to a private channel before discussing account details. For in-person help — device repairs, SIM swaps, trade-ins — T-Mobile and Metro by T-Mobile operate company-owned retail stores nationwide, and the store locator lets you book an appointment ahead of time. One practical tip: customer care opens at 4 AM Pacific, so calling in the first hour or two on a weekday usually means the shortest hold.
Mailing Addresses for Correspondence and Disputes
Letters sent to the Bellevue corporate office are not the fastest route to a resolution. T-Mobile publishes a dedicated Customer Relations mailbox in Albuquerque on its contact page, and the same address is named in the carrier’s Terms and Conditions as the place to send a formal Notice of Dispute before arbitration:
| Customer Relations / Notice of Dispute | T-Mobile Customer Relations, P.O. Box 37380, Albuquerque, NM 87176-7380 |
| Bankruptcy legal notices | T-Mobile, P.O. Box 53410, Bellevue, WA 98015-3410 |
| Corporate office (no customer correspondence) | T-Mobile US, Inc., 12920 SE 38th Street, Bellevue, WA 98006 |
Bill payments should go through the T-Life app, t-mobile.com, or the automated line at 1-800-937-8997 rather than by mail to any of the addresses above — the remittance address printed on your paper statement is the only one set up to process checks.
Company Background
T-Mobile’s American story starts in 1994, when John Stanton spun VoiceStream Wireless out of Western Wireless to build a GSM network in the western United States. Germany’s Deutsche Telekom bought VoiceStream in 2001 and rebranded it T-Mobile USA the following year, planting the magenta logo in Bellevue. The modern public company, T-Mobile US, Inc., was created on May 1, 2013, when T-Mobile USA combined with MetroPCS and began trading on NASDAQ under the ticker TMUS — the same year the company launched its “Un-carrier” strategy of scrapping annual contracts and overage fees.
The defining milestone came on April 1, 2020, when T-Mobile closed its merger with Sprint, vaulting from a distant third to the second-largest U.S. wireless carrier and inheriting the Overland Park campus. Growth has continued since: in August 2025 T-Mobile completed its purchase of UScellular’s wireless operations, and it has expanded into home broadband through 5G Home Internet and fiber joint ventures. As of December 31, 2025, the company reported approximately 75,000 full-time and part-time employees and 142.4 million postpaid and prepaid customers, according to its annual report. Deutsche Telekom remains the controlling stockholder.
Leadership
Srini Gopalan became President and Chief Executive Officer on November 1, 2025, succeeding Mike Sievert, who moved into a newly created Vice Chairman role after leading the company through the Sprint merger. T-Mobile announced the transition in a September 2025 newsroom release; Gopalan had been Chief Operating Officer and previously ran Deutsche Telekom’s German business. Like most large U.S. public companies, T-Mobile US, Inc. is incorporated in Delaware even though it operates from Washington state — our Delaware business search guide explains how to look up the corporate registration, and the Washington business search guide covers the state where the headquarters and operating subsidiary T-Mobile USA, Inc. are registered.
Key Office Locations
Bellevue is the official home, but the Overland Park campus is nearly as important — it houses network operations, business support teams, and a large Customer Experience Center, and it is the second-biggest concentration of T-Mobile employees in the country at roughly 3,500 people. That second headquarters made headlines in late 2025 when T-Mobile said it could not share the Aspiria campus with a proposed Kansas City Royals ballpark and would look for a new Kansas City-area home if the stadium went ahead; in January 2026 the Royals ruled the site out, and T-Mobile’s lease there runs through mid-2029. Beyond the two headquarters, T-Mobile operates a network of Customer Experience Centers around the country that handle customer care, and its Customer Relations mail operation runs out of Albuquerque, New Mexico.
Dealing with Customer Complaints
Start with customer care: dial 611 or 1-800-937-8997, or open a chat in T-Life, and write down the date, the representative’s name, and the case or interaction number. If the first agent cannot fix it, ask for a supervisor — and if that fails, ask for the case to be escalated to T-Mobile’s Executive Response team, the internal group that handles complaints on behalf of the executive offices. You can also put the complaint in writing to T-Mobile Customer Relations, P.O. Box 37380, Albuquerque, NM 87176-7380, including your account number and what you want done.
Because T-Mobile is a wireless carrier, you have a federal regulator on your side. File a free informal complaint with the Federal Communications Commission; the FCC forwards it to the carrier, which must respond in writing within 30 days, and these complaints are typically routed to a senior resolution team rather than the regular call center. Your state public utility commission or attorney general’s consumer office can take billing and service complaints too. As a last resort, T-Mobile’s terms require you to mail a written Notice of Dispute to the Customer Relations address above, after which you can pursue arbitration through the American Arbitration Association or take a qualifying claim to small-claims court.
Summary
T-Mobile’s headquarters is at 12920 SE 38th Street, Bellevue, WA 98006, with a second headquarters on the former Sprint campus in Overland Park, Kansas — but customers get results through other channels: 611 or 1-800-937-8997 for daily customer care, the T-Life app for round-the-clock self-service, the Albuquerque Customer Relations mailbox for written complaints, and the FCC when escalation is needed. Looking for another company’s corporate contacts? Browse our other headquarters guides.
Frequently Asked Questions
Where is T-Mobile’s headquarters located?
T-Mobile US, Inc. is headquartered at 12920 SE 38th Street, Bellevue, WA 98006, in the Factoria area of Bellevue, Washington. The company also maintains a second headquarters on the former Sprint campus in Overland Park, Kansas.
What is T-Mobile’s customer service phone number?
Dial 611 from any T-Mobile phone or call 1-800-937-8997. Customer care representatives are available daily from 4 AM to 9 PM Pacific Time; the T-Life app offers self-service 24/7 and live chat until midnight Pacific.
Who is the CEO of T-Mobile?
Srini Gopalan has been President and CEO of T-Mobile US since November 1, 2025. He succeeded Mike Sievert, who now serves as Vice Chairman.
Who owns T-Mobile?
T-Mobile US is a public company traded on NASDAQ under the ticker TMUS, but Germany’s Deutsche Telekom AG holds a majority of the shares and is its controlling stockholder.
How do I file a complaint against T-Mobile?
Call 611 or 1-800-937-8997 and ask for a supervisor or the Executive Response team if the first agent cannot help, or write to T-Mobile Customer Relations, P.O. Box 37380, Albuquerque, NM 87176-7380. If that fails, file a free complaint with the FCC at consumercomplaints.fcc.gov, which requires the carrier to respond.
What is the T-Mobile corporate office address for legal notices?
The corporate office is T-Mobile US, Inc., 12920 SE 38th Street, Bellevue, WA 98006. A formal Notice of Dispute under T-Mobile’s terms must instead be mailed to T-Mobile Customer Relations, P.O. Box 37380, Albuquerque, NM 87176-7380, and bankruptcy notices go to P.O. Box 53410, Bellevue, WA 98015-3410.