During mass network outages, how come credit works but not debit?

Question

If you’re Canadian, you’re probably experiencing a network outage right now.

In: 33

Answer 1

A lot of answers here are pointing out how credit cards can work offline. While true, not relevant to what we experienced in Canada today. The short version is that debit systems are national (a Canadian debit card doesn’t work in foreign countries, except at specific ATMs on international networks) but credit cards are international. Canadian debit (Interac) system is exclusively on Rogers network, which is what went down. If Bell went down instead, debit would still have worked. Credit is on international networks, with tons of redundancies built in, so if networks go down, it’s simpler to swap. If all networks in a country went down, we wouldn’t be able to use real-time credit card transactions either (could still use some of the old-style manual credit card transactions).