If you have a smartphone, you probably receive text messages. Security codes from your bank, coupons from restaurants, messages from political campaigns ̵
Text messages do not contain the kind of 'Unsubscribe' links found in email newsletters. They often do not include instructions to unsubscribe. But even if a text message doesn't have instructions to stop it, there is a practically universal way to unsubscribe.
To opt out of automated text messages sent to your mobile phone number, reply to the SMS with one of the following words:
- QUIT  CANCEL
"Stop" and "Unsubscribe" among the most common commands.
These are fairly universal commands, and most automated systems will immediately notify you that you have been removed from the list and will no longer receive automated warning messages.
What About Spammy Texts?
The above tip works for legitimate automated SMS lists that provide a way to unsubscribe. As with spam emails, some people send spam text messages and don't stop even if you ask them nicely.
If someone keeps texting you anyway and you can't unsubscribe, you can always block text messages from specific number on iPhone or Android.
When you receive spam-like text messages from multiple numbers. You can block spam text messages on an iPhone or on an Android phone by installing a third party app that automatically blocks a known list of spam text numbers. It's like a spam filter for your text messages.