The short answer
Why it happens
"Spam Likely," "Scam Likely" and "Spam Risk" are applied by the called person's own mobile carrier, using three analytics companies, one per major carrier. A number carries a reputation the way an email sender does; a handful of complaints is enough to flag it, and a flag does not clear itself. Every call we place is signed at the highest attestation level, which tells the carriers the caller is verified to use the number, but signing does not erase a reputation.
Register the number
The first step is yours and it is free: the Free Caller Registry. One submission reaches all three analytics companies. The form asks for the legal business name, address, website, a contact, the purpose of your calls, the rough monthly volume, and up to twenty outbound numbers.
Register the number that shows as your outgoing caller ID, usually the main or menu number rather than each person's extension. Every number your business calls out from carries its own reputation, so include each one that shows.
What the scoring watches
Rotating through numbers is the pattern the engines are built to catch. A number used for one purpose, whose calls are answered and whose unanswered calls leave voicemails, scores well. Complaints about texts feed the same picture, which is why a text blast done wrong can label your calls.
If the label stays
Registration is not a guarantee; where there are many user reports, a number can stay labeled. Tell us, and we follow up with the analytics company directly, with the number, a description of your business and how it calls, and the fact that every call is signed. Adjustments have been made that way before. Two carriers also take disputes on their own pages: Verizon and T-Mobile. No outcome is promised by any of them, and no service sells a whitelist; paid monitoring products sit on top of the same free registration.
Your caller ID name
The name that shows beside your number is a separate setting, on each number's page in the portal. See extra numbers, caller ID, and international calls.