To filter invalid phone numbers, we could delete every outbound call that failed.

In Reporting --> Call Report, there's a call status that is "failed".

In automations, we can choose the "Call Status" trigger, but we can't chose "failed" as a call status. There's only "busy", "canceled", "completed", "no answer" and "voicemail".

We have 28% of failed outbound calls and plan on making more than 35 000 calls per month in the future, it would save us loads of time.