How to Block a Phone Number on T-Mobile
If you're being troubled with unwanted calls or text messages, block the number on a T-Mobile phone using your phone's settings or with Family Allowances.
With a T-Mobile phone, there are two different ways to block phone numbers from calling you, leaving you voicemail messages or sending you texts. Most phones today have a way to block numbers using settings. If your phone doesn't have this option, you can use the options in T-Mobile's Family Allowance Plan.
Block Numbers With Family Allowances
If you have the Family Allowance Plan, you can block individual numbers from My T-Mobile for yourself or anyone in your family.
Log into your My T-Mobile page and click Tools. Select Access Family Allowances from the Family Allowances menu.
Click the Allowed Numbers option and enter the 10-digit phone number in the Never Allowed text field, then click OK.
Block Numbers From an Apple iPhone
On an Apple iPhone use the Block Contact feature available in iOS 8 to prevent specific numbers from calling you, sending you text messages and contacting you with FaceTime.
Select the number from the Phone, Messages, Contacts or FaceTime app. Tap Details if you're using Messages. Tap the Info button.
Scroll to the bottom of the screen. Select Block This Caller.
Tap Block contact to confirm your selection. If you made a mistake or change your mind, you can select Unblock This Caller from the numbers Info screen or from the person's screen in Contacts.
Blocking From a Samsung Galaxy
Samsung Galaxy phones, like the Galaxy S4, S5, S6 and S6 edge also have a feature to block numbers using the Spam Settings.
Tap Messaging from the Home screen.
Tap Menu. Scroll to the bottom of the screen and tap Settings.
Tap the Spam Settings check box if it doesn't already have a check mark in it. Tap Add to Spam Numbers.
Tap the + icon and enter the 10-digit phone number you want blocked.
Blocking From a Nexus 6
The Nexus 6 gives you the ability to send unwanted phone calls directly to voicemail so you won't have to hear the calls. Text messages are automatically blocked too, so you won't have to look at them.
Enter the phone number as a New Contact in the Contacts app.
Tap the pencil-shaped Edit icon and then the More icon with three dots.
Tap the All Calls to Voicemail option.
Blocking From an HTC One M9
Select Apps from the Home screen. Tap People and then tap the Menu icon.
Tap Manage Contacts. Select Blocked Contacts.
Tap the Add icon and select From People or Add Number.
Select the contact or enter the number you want blocked and tap OK.
Blocking From an LG G3 or G4
Select Apps and tap Settings.
Tap Call, then Call Reject and then Reject Calls From.
Tap the Add icon and then select Contacts, Call Logs or New Number.
Select or type the number you want blocked and tap Save or Done.
Remove your phone number from telemarketing lists by registering it with the FTC's National Do Not Call Registry. Once your number has been registered for 31 days, you can file a complaint with the FTC if a telemarketer continues calling you.
If you're really being harassed by text messages, T-Mobile offers a free Message Blocking service to block all SMS text messages, MMS picture messages and IM instant messages. This service isn't available on prepaid plans and won't block everything. For example, it won't block phone calls, voicemail, as well as BlackBerry or Windows Phone messages and email. It will stop annoying spam text messages -- along with texts from everyone else -- using SMS, MMS or IM.