Glossary

What is Carrier filtering?

Carrier filtering is the automated screening mobile networks apply to business text messages, blocking or throttling traffic they judge to be spam.

Filtering happens after a message is accepted for delivery, which is why a campaign can report messages as sent while a meaningful share never reaches a phone. Carriers rarely explain individual blocks.

Common triggers include public URL shorteners, unregistered or newly registered numbers, high send velocity, and message content that resembles known spam patterns.