In India, we often receive SMSs which do not actually have a number, but instead, have a name like 'VK-AMSWAN'. SMS blockers like Truecaller don't have any facility to recognise such senders and keep asking for a number to block.

When using third-party SMS apps like Chomp SMS, there is an option to show the contact number below the contact name. Guess what it shows for the spam?

  • VK-AMSWAN (name)
  • VKAMSWAN (where the number shows up for other contacts)

How do I block such senders? I cannot blanket block all unknown SMSs because even banking information comes from such named senders.

It seems SMS blocking isn't as well developed as call blocking is. Truecaller actually rejects spam calls without you ever knowing about them. No SMS blocker I've seen has this facility so far. All they do is receive the messages and hide them. If someone can locate a method to fully block spam SMS, please do tell. :)

  • 1
    Use DND(Do-Not-Disurb) services of your service provider instead. It will block unwnated sms messages.
    – Lucky
    Jul 15, 2015 at 11:10
  • 1
    I think there is no other way. Try activating DND (Do Not Disturb) from your mobile carrier
    – samnaction
    Jul 15, 2015 at 11:11
  • Already using it. Problem is, the national DND registry can only block those services which are already registered. What about those that aren't?
    – user116947
    Jul 15, 2015 at 11:13
  • did u try clicking the call button ? I do notice they having a seven digit number
    – Sam
    Jul 15, 2015 at 11:29
  • Don't see the call button anywhere. Even if it was, how would you call a number that isn't really a number?
    – user116947
    Jul 15, 2015 at 14:18

3 Answers 3


Since you told DND doesn't block these kinds of messages, you can use Textra SMS from the Play Store, select the message that you received, and select the "Blacklist" message option to stop receiving the SMS.

If you still want those messages to be received but not to get a notification, you can select the "Crossed Bell" icon at the top to not notify on receiving the message so that it is stored in your inbox for future use but will not be notified to you.

Using Textra, I found another feature to find out the number of those LM-*, TM-*, and VK-* series kind of SMS messages. Open Textra and swipe the message to the left to reveal the call feature. Double-tap the call button and it calls the number. So, now you've got the number, and this way you can block those numbers from receiving those text messages. I tried that and showed the numbers to me for every message in my inbox with XX-* SMS messages. ;)

  • I was looking for a more generic solution present in Android itself, but that seems to be the only way now. Sigh. MANI's answer says Truemessenger can use keywords to block, so I think that must be the most general solution available for now. Android should provide blocking features in the OS itself.
    – user116947
    Jul 15, 2015 at 23:04
  • @Andy356 I see. Check my updated answer too. It might be helpful to reveal those unknown senders number incase for blocking. ;)
    – Lucky
    Jul 16, 2015 at 6:56
  • 2
    Did you know that in SMS spec the actual phone number is not mandatory and it is only informative, one could actually send SMS without any numbers revealed to receiver. Even while gateway only requires receiver number it is not required to forward it. And when it comes to sender gateway wont do anything with that. How do I know? As I've developed sw interfaces for those services... Jul 17, 2015 at 1:05
  • Tried the 'calling through Textra' option. What it does is just convert the letters to numbers through some unknown operation. Checked it thoroughly. The number of digits are always equal to the number of letters.The numbers never exist. So tough luck for me. :(
    – user116947
    Jul 18, 2015 at 11:24
  • @SampoSarrala That is the problem here. A lot (A HUGE MANY) services in India use this ability to send spam SMS to people, without them ever being able to contact back, or block, because blocking requires a number.
    – user116947
    Jul 18, 2015 at 12:28

You can block SMS messages from a specific sender like this using stock Android on a Google Pixel or similar phone, using the app Messages by Google. For example, if you receive a message from "VK-AMSWAN" (with no phone number), you can block all further SMS messages from "VK-AMSWAN". There isn't a way to block messages from all senders without a phone number all at once, though.

Other phone manufacturers have their own SMS app, and they might not provide this functionality.


If you're using the Hangouts app, open the conversation that the sender has sent. Once in it, select the Menu button (3 vertical dots in the top right) and select "People & options". On this screen, you should see the option to "Block VK-AMSWAN" (or whatever the sender's name is).

This article has a more detailed description of these steps with screenshots.

  • Yes, using Hangouts. Already tried that, but it only mutes notifications from that sender. :( Similar to the Crossed Bell feature in Textra that Lucky's answer is talking about.
    – user116947
    Jul 15, 2015 at 22:56
  • Fast forward to 2022, Google Hangouts is not available anymore and has been replaced with Google Chat and Google Meet, which AFAIK doesn't support SMS anymore. On the other hand, there's also Google Message which is mentioned in Flimm's answer.
    – Andrew T.
    Jul 14, 2023 at 18:15

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