Facebook have an awesome feature of sending sms notification to your mobile phone number whenever you receive the selected notification on facebook profile.
However, this feature sometimes gets on nerves! One thing that adds to it is multiple mobile numbers 
through which facebook sends the sms message and also, you get notified on mobile phone via sms even if you are logged into facebook and online! seriously irritating isn’t it?
However, this article is for those people, who want to use ht facebook sms notification feature, but want to turn it off once they are logged into the facebook through their computer of mobile devices.
To stop facebook from sending you sms notifications when your are online on facebook, follow these steps:
- Login to your Facebook profile
- Goto: (top right menu) Account > Account settings
- On the account settings page, goto Mobile from the page sub menu
- On that page, find the section asking about What times should texts be sent to my phone?
- Select the option below it saying: Do not send me SMS notifications while I am using Facebook
- Click save preferences
This way you will not get sms notifications when you are logged into Facebook.