Open the spam text
Tap the sender name or number
Tap Info
Tap Block this Caller
Go to Settings
Tap Messages
Turn on Filter Unknown Senders
Go to Settings
Tap Phone
Turn on Silence Unknown Callers
Report the message as junk if the option appears
Delete the spam text
Do not reply to spam texts
Do not tap links in spam texts
Contact your carrier to enable spam filtering
Update iPhone to the latest iOS version
Use a third-party spam blocking app if needed