How Credit Card Networks Work in Canada: Visa vs Mastercard vs Amex

When you tap a credit card in Canada, two different companies are usually involved, and people mix them up constantly. There is the network printed in the corner, like Visa, Mastercard, or American Express, and there is the issuer, the bank or company that actually lent you the money and sends your statement. Understanding the split explains why your card works almost everywhere but gets declined at Costco, why an Amex sometimes earns more, and why merchants occasionally ask you to use a different card. This guide is educational only and is not financial advice. Always confirm current terms on official network, issuer, and government pages.

Networks versus issuers

A card network operates the rails that move money and information between banks. Visa and Mastercard do not issue cards to consumers or lend money themselves. Instead, they connect the cardholder's bank (the issuer) with the merchant's bank (the acquirer) and set the rules for how transactions clear. So a TD Visa and a CIBC Visa share the same network but are issued, priced, and serviced by different banks.

American Express works differently. On many of its cards, Amex is both the network and the issuer. It runs its own rails, holds the relationship with the cardholder, and deals with the merchant side too. This closed-loop model is part of why Amex can offer rich rewards and tightly themed perks, and also part of why its acceptance footprint is smaller than Visa's or Mastercard's. To add nuance, some Amex-branded cards in Canada are issued by banks under licence, but the flagship Amex products are issued by American Express itself.

The practical takeaway: the logo tells you where the card is accepted, while the issuer and the specific product determine your rewards rate, annual fee, interest rate, and benefits. Two cards on the same network can be wildly different. See the glossary for short definitions of issuer, acquirer, and interchange.

Acceptance in Canada

Visa and Mastercard are accepted at the vast majority of Canadian merchants that take credit cards. For everyday spending, you can treat them as interchangeable on acceptance. Amex is the one to watch.

Amex acceptance in Canada has improved dramatically, but a gap remains. American Express reports that over 110,000 places in Canada started accepting its cards in 2023 alone, a sign of fast growth. Even so, some smaller independent shops, certain trades, and a handful of large retailers still take only Visa and Mastercard. That is why many Amex holders carry a Visa or Mastercard as a backup card.

The most famous acceptance quirk is Costco. Because of an exclusive payment partnership, Costco Canada warehouses accept Mastercard credit cards but not Visa or American Express. According to Costco Canada's official customer service page, warehouses accept Mastercard, debit, cash, the Costco Shop Card, personal cheque, and Apple Pay. Online at Costco.ca, both Visa and Mastercard work. If you shop there often, the network on your card matters more than the rewards rate, so review our best cards for Costco breakdown before you pick.

A few other patterns are worth knowing. Some merchants accept Amex but route it as a separate option at checkout, and a small number of businesses add a surcharge for credit card payments where permitted. None of this changes the core point: in Canada, Visa and Mastercard give you the broadest acceptance, while Amex offers strong rewards with a narrower, fast-growing footprint.

Interchange and why it shapes rewards

Every time you pay by credit card, the merchant pays a processing cost. A large slice of that is the interchange fee, set by the network and paid by the merchant's bank to your issuing bank. Interchange is usually a percentage of the purchase, sometimes with a flat component. That money flowing back to issuers is a major reason your card can offer cashback, points, and travel perks. Higher interchange tends to fund richer rewards, which is part of why premium and Amex cards often earn more and also cost merchants more to accept.

This is also where acceptance gaps come from. Merchants weigh the cost of accepting a network against the sales they might lose by refusing it. Amex's fees have historically been higher, which is one reason some merchants declined it, though Amex has been closing that gap as it expands acceptance.

Interchange has been a live public-policy issue in Canada. The Government of Canada announced in 2023 that it finalized agreements with Visa and Mastercard to lower credit card transaction fees for small businesses, a move aimed at reducing what merchants pay. Separately, the Competition Tribunal heard a case (CT-2010-010) about network rules such as the no-surcharge rule, which limited how merchants could steer customers toward cheaper payment methods. The Tribunal dismissed the application but noted competitive concerns and pointed to a regulatory framework as the appropriate fix. The details matter less than the direction: regulators have repeatedly scrutinized interchange because it ripples through both merchant costs and consumer rewards.

What this means when choosing a card

Start with where you shop. If Costco is a regular stop, you need a Mastercard for in-warehouse purchases, full stop. If you want the deepest rewards and do not mind carrying a backup, an Amex can pay off, paired with a Visa or Mastercard for the places that do not take it.

Then compare on the things the issuer controls, not the network logo: the earn rate in your top spending categories, the annual fee, foreign transaction fees, and the welcome offer. The Financial Consumer Agency of Canada is a good neutral starting point for understanding how card features and fees work before you commit. If you want to keep costs down while you learn how networks fit your spending, a no annual fee card is a low-risk way to start.

A simple rule of thumb for most Canadians: hold one Visa or Mastercard for universal acceptance and one rewards-focused card (often an Amex) for the categories where it earns the most. That combination covers nearly every checkout in the country while letting you optimize rewards where acceptance allows.

Card terms, acceptance, and fees change over time. Nothing here is financial advice, so always confirm the current details on the official network, issuer, and Government of Canada pages before applying.