By default, only your Snapchat friends can contact you on Snapchat. You may see messages from people in your phone’s Contacts if they reach out before adding you as a friend on Snapchat.
When you receive a message from someone who is not your friend on Snapchat, you can tap ‘Report or Block’ in the Chat to clear the conversation from your feed. The Snapchatter won’t know that you have hidden or blocked them.
You can also disable messages from non-friends in your Settings.
To disable messages from non-friends…
- Tap ⚙️ in your Profile to open Settings
- Tap ‘Who Can Contact Me’
- Select ‘Friends’