Blocking text messages on a Samsung Galaxy phone can be done through the phone itself, via third-party applications or through your service provider, depending on the extent to which you want to block incoming text messages.

To block text messages directly through your Samsung Galaxy device, you have two options. First, you can add the phone number you want to block to your contact list, open the contact, tap the menu key and select “Add to reject list.” The second option is to open a text message from the number you want to block, tap the menu key and select “Add to spam numbers.” Either of these settings can be undone on the same screens.

You can also add to and manage numbers on your auto reject list easily through the phone settings without having to add a number into your contact list. Simply tap the menu button on the home screen of your Samsung, tap "Settings," tap "Call Settings," tap "Call Rejection" and add or remove phone numbers to your call rejection list.

Via App
There are several apps available for the Samsung Galaxy that can block phone numbers from calling or texting your mobile number. Mr. Number, Truecaller, Caller ID & Block by Phone Warrior, WhosCall, Block SMS & Call by Sriseshaa, Hide My Text and Blacklist by AA.TK are just a few of many. The functionality of these apps varies, so try a few until you find one that has an interface and functionality you prefer.

Via Service Provider
It is also possible to block text messages by going directly through your service provider. Most standard – and free – blocks provided by your carrier will be "all-or-nothing" rather than specific number blocks. However, if you purchase certain additional features that bill at a set monthly rate – such as Smart Limits through AT&T – you will be given access to specific blocking functionality without needing direct access to the device on which you want to block text messages.