Especially since the onset of robodialing, the number spam phone calls has skyrocketed to well over 3 billion spam calls every month.  That’s why so many phone carriers have now implemented the “Spam Likely” tool, which flags phone numbers it believes to be spam and displays your number’s ID to the recipient as a likely spam call.  Carriers monitor how many recurring inbound calls their users receive from the same number, and block it once that number becomes excessive. There are also apps that help to filter out spam calls. In order to avoid having your business phone number filtered out as spam, you should:  Make phone calls from numbers with a variety of geographical area codes Obtain local phone numbers, and use the corresponding local phone number when placing outbound calls  Rotate your phone numbers when placing outbound calls Register your business telephone numbers with caller ID reputation agencies  Avoid calling the same numbers over and over again in succession