Cell phones and text messages allow you to communicate with anyone, anywhere, making communication faster than ever. That doesn't mean that text messages can't also be used harass and spam you with messages you don't want. Whether you block a number using your phone or your cell phone provider, you shouldn't be able to see text messages from blocked numbers. However, limitations of blocked numbers vary between phone providers.
The ability to block text messages varies both between providers and phones; the iPhone doesn't offer a tool to block text messages on the phone, although AT&T, Verizon and Sprint can handle blocking on a system level. Conversely, T-Mobile has no method for blocking specific text messages, but if you use an Android smartphone you can use an app to block text messages on that phone.
Blocking Messages and Smartphones
With smartphones becoming more popular, you have more options regarding how you block messages. The How-To Geek details applications for both Android and iPhones that allow you to block messages, although with the iPhone you must first jailbreak it to do so. These apps add a layer of security to messages and allow you to change your blocked numbers manually whenever you need to do so, without dealing with limitations of your cellular provider.
Specific Carriers and Blocking
T-Mobile offers no method for blocking specific numbers, but it offers a filter for stopping email-based text messages. Sprint offers a method to block not only incoming calls, but also outgoing calls to specific numbers. AT&T and Verizon both offer methods for blocking messages from your both by phone number and email. Contact your phone provider to discuss your call-blocking options.
Limitations of Blocked Numbers
Carriers have different limitations for blocked numbers. For instance, Verizon allows you to block only up to five numbers at a time and blocked numbers expire three months after the date of first blocking. You cannot block emergency numbers or system numbers. Verizon also prohibits blocking numbers that don't contain 10 digits. The person calling from the blocked number is alerted that he is blocked; it is not a secret.
You do not receive any voice messages from a blocked phone number. Users with a blocked phone number are not directed to your voice mail but are blocked entirely -- they do not gain access to leave any message on your phone, voice or otherwise. If you do get a voice mail from a number previous blocked, check with your phone provider to check that the number is still blocked.