[1][2][3] The system consists of infrastructure and standards for the presentation and distribution of public alerts issued by federal or provincial/territorial government authorities (particularly public safety authorities)—such as for weather emergencies, AMBER Alerts, and other emergency notifications—through all broadcasters and last-mile distributors in the affected region, including television stations, radio stations, television providers, and mobile networks in the affected region.

In April 2020, the RCMP faced criticism for not understanding and being slow to work with local officials in use of the system to warn of an active gunman, which had attacked multiple locations in the province of Nova Scotia.

[9][10] Establishment of such a system in a voluntary form was hampered by CRTC rules at the time, which required television providers to obtain consent from broadcasters before they could overlay emergency notifications onto their programming.

[15][16] Environment Canada, the Canadian Council of Emergency Management Organizations, and the provinces of Manitoba and New Brunswick endorsed the potential use of the NAAD framework as a backend for a mandatory public alerting system.

[17] On 27 February 2014, the CRTC issued a proposal to mandate participation in the national alert system by all television and radio broadcasters, and cable and satellite companies.

[11][18] Bell Satellite TV, MTS, Shaw Direct, and Sogetel did not fully participate in the system upon the deadline, as some of their customers utilized legacy set-top boxes that cannot be updated to support the display of public alerts.

]"[19][20] In December 2015, the CRTC granted an indefinite extension of the exceptions and reporting guidelines to Bell, Shaw Direct, and MTS until they completely phase out hardware that is not compatible with the NPAS.

The CRTC felt that the providers had made a good-faith effort in informing customers of their inability to receive public alerts and offering hardware replacements.

Messages are formatted using the Canadian Profile of the Common Alerting Protocol (CAP-CP), and are provided in at least one of Canada's official languages (either English, French, or both, as determined by local policies and laws).

On television and radio, relevant alerts marked with this flag are immediately presented to viewers when they are received, interrupting programming to facilitate their display.

The CRTC supported this position, officially requiring wireless service providers to participate in two public-visible alerts per year, distributed on all platforms.

[41][42] There is precedent for alert tests to be postponed or cancelled on a regional basis if there is an ongoing threat of an actual emergency in an area, such as for instance, Spring flooding in parts of Ontario and Quebec in May 2019.

[51] As the system was designed primarily to handle domestic situations such as weather, ECCC was initially the only federal agency capable of issuing alerts.

"[69] National Post columnist Matt Gurney provided similar praise, but noted that the system's operation hindered its ability to disseminate information quickly.

He explained that while the purpose of such a system is to "[get] information to the public as rapidly and as clearly as possible", on his television provider's set-top box "the text was arriving on my screen incredibly slowly.

[70] The first public awareness test to include Cell Broadcast transmission occurred in Ontario and Quebec on May 7, 2018, with the remaining provinces following suit on May 9, in observance of Emergency Preparedness Week.

In Quebec, a syntax error in the test message's XML file caused the wireless alert to fail, while users in Ontario reported mixed results.

[71] Testing in the remaining provinces and territories, excluding Nunavut, occurred May 9, 2018, again to mixed results, with people reporting having not gotten an alert despite their phones meeting the requirements.

[75] In September 2018, Scott Shortliffe, chief consumer officer of the CRTC, acknowledged that the effectiveness of the system was being affected by technical problems, following a province-wide AMBER Alert in North Battleford, Saskatchewan where the wireless cell broadcast was delayed by several hours (as well as complaints by Manitoba residents over the cross-provincial extension of the alert),[76] and mixed reports during tornadoes in the Ottawa-Gatineau region (including some users not receiving any message, and users in Quebec only receiving an English-language message).

[80][35][81] In a 2019 follow-up to his previous criticisms of the system, Gurney noted that several instances of AMBER Alerts issued during the early-morning hours in Ontario had prompted residents to call 9-1-1 to complain.

He also acknowledged similar opinions presented by Philip Cross in an editorial for its sister publication, the Financial Post; Cross felt that AMBER Alerts on phones should be optional as in the U.S., comparing the disruption of sleep caused by late-night alerts to health effects associated with daylight saving time, and noting that the public would be "more likely to arrive at better solutions if we can discuss the issue sanely, rather than have all complaints dismissed as callous disregard for children's safety.

"[82][83] In response to an Ontario AMBER Alert that concluded with the victim found murdered, a Maclean's columnist, Scott Gilmore, pronounced all critics of the system to be "horrible" and expressing entitlement for their refusal to participate in the civic duty of locating a missing child in imminent danger.

[84] In October 2019, a 70-year old resident of Hamilton, Ontario was charged with mischief for disrupting emergency services, after repeatedly calling 9-1-1 to complain about an AMBER Alert broadcast.

Solicitor General Sylvia Jones stated that the erroneous alert was the result of a mistake during a "routine training exercise" by Ontario's emergency operations centre.

MPP and Ontario NDP energy and climate change critic Peter Tabuns also responded, stating that "confidence in the accuracy of the [alert] system is essential for public safety.

[95] The Royal Canadian Mounted Police was criticized following a killing spree by Gabriel Wortman[96][97][98] on April 19, 2020 in Nova Scotia, for not having used the alert system to warn of the active gunman at-large.

Premier Stephen McNeil stated that he had not formally received any request for the issuance of an emergency alert, and explained that "I can tell you, I'm not going to second-guess why someone or the organization did what they did or didn't do at this moment in time.

RCMP Chief Superintendent Chris Leather stated that they had primarily relied on Twitter to issue timely updates on the situation due to its fluidity.

[99][100] However, the areas where the shootings occurred had poor internet access, and a large population of seniors (who may not necessarily be active users of social media).

[106][107] Emergency Management BC chose not to use the alert system during major floods in November 2021, with the province's Minister of Public Safety Mike Farnworth stating that "It is one tool.