What Is Simultaneous Substitution? Why US Shows in Canada Carry Canadian Ads

Flip to the CBS channel in a Canadian cable package during Survivor and the ads are for a Toronto car dealer, not a Cleveland one. That's no glitch. It's a rule dating to 1972 called simultaneous substitution.

Short version: when a Canadian station airs the same program at the same time as a US station, your cable, satellite or IPTV provider drops the American signal and shows the Canadian one on both channels.

• It covers cable, satellite and IPTV, not antennas or streaming apps.
• It's why CTV, Global and Citytv chase the US air time.
• The Super Bowl was pulled out in 2017, then put back after a 7-2 Supreme Court of Canada ruling on Dec. 19, 2019.

What is simultaneous substitution?

A swap. A distributor temporarily replaces one channel's signal with another channel showing the same program at the same time, usually a Canadian station laid over a US affiliate. Now and then a local Canadian station covers a distant Canadian one instead.

The CRTC's reason is money. Without the swap, one episode's audience splits across two stations and the Canadian rights holder sells fewer ads. The programs must be comparable and simultaneous, and the swap should end the moment either stops being true.

Who actually flips the switch?

Your provider, but only when the Canadian broadcaster asks. Distributors normally can't alter or delete a channel; simsub is the carved-out exception, requested swap by swap.

Cable and IPTV companies make the swap at a central facility before the feed reaches you. On satellite it happens at the uplink or inside your set-top box. Only conventional stations with an over-the-air presence can ask, so CTV, Global and Citytv qualify and cable-only channels don't.

Why do CTV, Global and Citytv air US shows at the same time?

Because the swap only works if the broadcasts line up. That's why Survivor on Global sits at 8 p.m. Wednesdays like CBS, and The Voice on CTV follows NBC's Monday slot.

The side effect: Canadian schedules are often set by US ones, and Canadian-made shows fill the gaps. Our map of which Canadian channel has your US show lays it out.

So why is my show a day late, or full of US ads?

Nobody has to simulcast. If a Canadian network picks another night or hour, the broadcasts don't match, simsub can't apply, and the US channel runs untouched, American ads included.

Dancing with the Stars on Citytv is the live case: Citytv's slot doesn't match ABC's, so the ABC feed stays watchable. A smaller local station can still get the swap, as CHCH does with Hell's Kitchen. Specialty channels can't; the CRTC ended that in 2015.

Does simsub apply to Crave or the Global TV App?

No. The rule binds cable, satellite and IPTV distributors, and a streaming app has no American signal inside it to cover.

A streamer shows whatever the Canadian rights holder uploads. CTV shows usually reach Crave the next day, while SNL streams there live. An antenna also escapes it: a US station you can pick up near the border arrives with its own ads.

What happened with the Super Bowl ads?

Canadians told the CRTC they wanted the American commercials, and the regulator agreed they were part of the event.

Bell Media and the NFL appealed; Bell said the ban cost it viewers and millions of dollars. The majority found the CRTC's power lets it order distributors to carry a channel, not set conditions on it. Nothing has replaced the order, and 2026 Super Bowl coverage still pointed Canadians online for the US ads.

Can a substitution cut off the end of my show?

Yes. US networks sometimes run a minute or two long, and a swap that ends on schedule can clip the last scene.

The CRTC said in 2015 that a station with repeated, substantial errors can lose the right to request swaps, and a distributor at fault can owe customers a rebate. Complain to your provider first, then the CRTC.

For this season's line-ups, see what's new in Canada next week or our CTV, Global and Citytv coverage. Our sister site covers where to watch Canadian reality TV and fall 2026 reality premieres.

Frequently asked questions

Is simsub why I can't see US Super Bowl commercials?
Yes. Since 2020 the game is swapped like any other simulcast.

Does it happen in Quebec?
Far less. The CRTC says simsub happens primarily in the English-language market.

Can my provider refuse the swap?
Not once the station asks. It's set out in sections 38 and 51 of the Broadcasting Distribution Regulations.

Sources

• CRTC: Broadcasting Regulatory Policy 2015-25
• CRTC: Simultaneous Substitution Working Group report
• Supreme Court of Canada: 2019 SCC 66, case in brief
• The Globe and Mail: Super Bowl commercials ruling
• Wikipedia: Simultaneous substitution
• iPhone in Canada: Super Bowl 2026 in Canada

By the Watch Canada On Air desk · Updated Sept. 27, 9:45 a.m. ET