Mobile carriers, handset makers and call-screening apps score the numbers that call their users. A number that places many short calls, gets few answers or collects complaints can be labeled as spam ("Spam likely", "Suspected telemarketing") or blocked outright. The person you call sees the warning before deciding whether to answer, so a flagged number pulls down the connect rate of a whole campaign.
Reputation is held per number and per database, and the databases differ by country and provider. Common causes of a poor score:
- High daily call volume from a single number
- Many very short or unanswered calls
- Calls to people who did not expect them, followed by complaints
- Recycled numbers that were flagged under a previous holder
Good practice is to check numbers before a campaign starts, spread volume over enough numbers for the call load, call people who expect to hear from you, honor opt-outs and retire numbers that stay flagged. Rotating numbers only to stay ahead of blocking does not fix the cause and can breach carrier and regulatory rules.
OVOKY caller ID reputation runs bulk spam checks of your numbers against reputation databases covering France, Belgium, Switzerland and Spain, as background jobs with history, and lets you export the clean numbers.