T-Mobile Customer Service Phone Numbers and Contacts. If you experience any problems with the T-Mobile service, have difficulties logging in, or would like to make a suggestion or complaint, you can call the customer service line. T-Mobile's Customer Service phone number is: 1-800-T-MOBILE (1-800-866-2453). Alternatively, if you are calling from a mobile connected to the T-Mobile network, you can simply dial 611 instead. Customer Support employees are available from 3 a.m. to 10 p.m. PT, every day. Automated phone help is available 24 hours a day, 7 days a week. However, if you are currently using a different wireless network operator, but wish to get in touch with T-Mobile with a question or query, you will instead need to call a separate line on +1 877-746-0909. T-Mobile International Callers Customer Care Phone Number. For international callers, the number to use is: 1-505-998-3793. Calls to this number from a T-Mobile connected device will not be subject to the usual long-distance charges, however, calls from landlines and other networks will be. This number is available between 3 am and 10 pm PT, seven days a week. T-Mobile Business Customer Service Phone Number. T-Mobile Business customer service can be found on: 1-888-537-4242. UK T-Mobile Customer Service phone Number. United Kingdom customers should call 150 from their handsets or call +44 0845 412 5000 the reach the UK customer service. International callers should call the UK number: +44 0207 362 0200. T-Mobile Tech Support Phone Number. If you still have problems, with your phone or with your coverage, you can contact a T-Mobile Specialist on: 1-844-326-2223. T-Mobile Phone Number for Bill Pay. In order to pay your bill via the phone, call: 1-877-453-1304. You can also pay your T-Mobile bill by downloading and logging in to the T-Mobile App. The procedure is as follows: \tOpen the app. You can download the app from iTunes or Google Play. \tOn the home screen, choose Pay Bill. \tSelect the amount you're paying. \tSelect the payment method. \tSelect the date that you want to make the payment. \tSelect AGREE & SUBMIT. T-Mobile Customer Service Mail Address. Finally, if you would prefer to write a letter to the T-Mobile customer relations department, the mailing address to use is: \tT-Mobile Customer Relations, PO Box 37380, \tAlbuquerque, NM 87176-7380. \tUSA T-Mobile USA Headquarters Address and Phone Number. The T-Mobile corporate office can be contacted by mail at: T-Mobile USA, Inc. 12920 Se 38th St. Bellevue, WA 98006 USA T-Mobile USA Headquarters Phone Number: (425) 378-4000. T-Mobile USA Headquarters Fax (425) 378-4040. T-Mobile USA, Inc. is a subsidiary of Deutsche Telekom. The postal address of the Deutsche Telekom Headquarters is: Deutsche Telekom AG Friedrich-Ebert-Allee 140 53113 Bonn Germany T-Mobile Community Support Forum. You can ask questions and see previous answers from other users and T-Mobile representatives at the T-Mobile Community Forum. T-Mobile Social Media Help. The company also have a Twitter Help service available for minor issues. Tweet at the handle @Tmobilehelp or visit https://twitter.com/tmobilehelp?langen, to ask a question. The T-Mobile Facebook page can be found here. Message the T-Mobile Customer Service Team. By logging in to your MyTMobile account, from a PC or from within the app, you can send a message to the customer support team and receive an answer on the go. Visit the Contact Us page, click on 'Message Us', and log in. Please share your complaints, praise or tips about T-Mobile's customer service, in the comment section below.