Robocalls / Press1

The Federal Communications Commission (FCC) has taken steps to address the Robocall problem by adopting rules that allow carriers to proactively block certain kinds of calls that are likely to be unlawful because they come from improper or invalid phone numbers, including those that do not or cannot make outgoing calls. Check out the details on the new FCC ruling here:


In accordance with these new FCC rules, OneCentVoIP and our vendors may begin blocking the following types of calls:

  • UNALLOCATED: Any call that contains a phone number in the ANI / From field that has not yet been assigned from the North American Numbering Plan.
  • ALPHA-NUMERIC: Any call that contains letters and/or alphanumeric data in the ANI / From field.
  • INVALID: Any call that contains a character string of digits or letters that does not fully comply with E.164 formatting and the Local Exchange Routing Guide (LERG). This includes ANI / From fields with all digits of the same number, or anything less than 10 valid digits assigned from the North American Numbering Plan.

With this change, you may see an increase in 503 SIP Response messages. If you encounter a 503 (service unavailable) response code in your SIP Signaling with OneCentVoIP, please check your traffic to ensure the above types of unlawful robocalls are not sent to OneCentVoIP from your network.


In the case you are NOT using a valid caller ID at this point, please contact us immediately in order to obtain a proper caller ID DID.

Make sure to register for the Robocall Mitigation Database.