I wonder what sort of hoops I'll need to jump through to create an "attestation" for my SIP provider that proves the legitimate spoofing of my outbound VoIP cal

I wonder what sort of hoops I'll need to jump through to create an "attestation" for my SIP provider that proves the legitimate spoofing of my outbound VoIP calls (to my main business number) is okay. As of right now, they have no way to do this. I expect that my outbound VoIP calls will begin to get automatically blocked at some point...