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Universal Call Blocking

Here’s everything you need to know about Universal Call Blocking and how it will impact you, including protecting you from unsafe calls.

What is Universal Call Blocking (UCB)?

Universal Call Blocking is a CRTC mandate (CRTC decision 2018-484) to block all incoming voice calls that have malformed calling line ID information. This applies to all Canadian service providers. Malformed calling line ID information contains telephone numbers that do not comply with North American or International numbering plans.

How will Universal Call Blocking affect me?

Universal Call Blocking will prevent you from receiving calls with calling line IDs that have malformed numbers.

How does Universal Call Blocking work?

Any incoming call with a malformed calling line ID will likely be blocked by the destination party’s service provider.

How can I tell if a number is malformed?

Generally, any number that does not comply with the North American Numbering Plan or international standards will be blocked. 000-000-0000, 111-111-1111 or numbers with more than 15 digits are examples of non-compliant numbers.

Can I opt out of Universal Call Blocking?

No, Universal Call Blocking is a CRTC- mandated service that applies to all customers.

Will Universal Call Blocking work on any device?

Yes, Universal Call Blocking is a network level solution that is applied to all incoming voice calls for wireless, IP and landline phones.

Will I be charged for this?

No, the Universal Call Blocking is free of charge.

Will Universal Call Blocking impact chatr customers roaming in the U.S. or any other country?

Yes, Universal Call Blocking rules will still apply while roaming out of Canada.

Why am I still receiving spam calls from numbers that appear legitimate?

Universal Call Blocking only blocks calls with malformed calling line IDs. Unfortunately, this may not stop all spam calls.

CRTC Resources

  1. Register with the National Do Not Call List (DNCL). This will reduce the number of telemarketing calls you receive.
  2. File a complaint about any call you received that violated one of the Unsolicited Telecommunications Rules.
  3. For additional information and resources, visit