Debit vs credit processing costs in Canada: what your mix really costs you

Most Canadian merchants think about processing costs as one number — "my rate." But in Canada, debit and credit are priced in fundamentally different ways, and the split between them on your statement matters more than the headline rate you were quoted. Two businesses with identical monthly volume can have wildly different fair prices, purely because one sells mostly on Interac debit and the other mostly on credit.

This article explains why Interac debit is different, when debit-heavy businesses quietly overpay, and how to read your own debit/credit mix to figure out which pricing model actually fits your business.

Why Interac debit pricing is fundamentally different

When a customer pays with a credit card, the largest component of your cost is interchange — a percentage of the sale set by the card networks and paid to the customer's issuing bank. A premium rewards Visa on a $500 sale costs meaningfully more to accept than a basic card on a $20 sale, because the fee scales with the amount.

Interac works differently. Canada's domestic debit network prices in-store transactions as a flat fee per transaction — typically pennies, not a percentage. Whether the customer taps their debit card for a $6 coffee or a $600 grocery run, the underlying network cost is roughly the same small, fixed amount. (See the Interac debit entry in our glossary at /resources/glossary#interac-debit.)

That structural difference is the whole story. Credit costs scale with your revenue; in-store Interac debit costs scale with your transaction count. Any pricing plan that ignores that distinction is averaging two very different things — and someone is paying for the difference.

The flat-rate trap for debit-heavy businesses

Flat-rate plans — one blended percentage on every sale, popularized by app-based processors — are marketed as simple. And they are. But apply a percentage to an Interac debit sale and think about where that money goes: the network charged your processor a flat fee measured in cents, and you paid a percentage of the ticket. On a $100 debit sale at a typical flat rate, most of what you paid is not covering any network cost at all. It is pure margin for the processor.

The bigger your average ticket and the higher your debit share, the worse this gets. A convenience store, grocer, dépanneur, gas bar, or quick-service restaurant doing 60–80% of sales on debit can be handing over multiples of the true network cost on the majority of its transactions, month after month, without a single line on the statement flagging it.

This is why the same flat-rate plan can be a reasonable deal for an online boutique running almost entirely on credit cards — and a genuinely bad one for the pizzeria next door.

Contactless debit vs chip-and-PIN: routing matters

There is one more wrinkle worth knowing. When a customer inserts their debit card and enters a PIN, the transaction routes over the Interac network at that flat per-transaction cost. When they tap, the transaction is contactless (Interac Flash), and depending on the card and how the transaction is routed, the fee structure can differ from a straight chip-and-PIN debit transaction.

For most merchants the difference is small, but it is not zero — and on high transaction counts it adds up. If your statement breaks out contactless debit separately from chip-and-PIN debit, compare the per-transaction costs. If it doesn't break them out at all, that opacity itself is a signal about how your processor prices debit.

Dual-network cards and online debit

Look closely at a Canadian debit card and you will often see two logos: Interac, plus Visa Debit or Debit Mastercard. These are dual-network (co-badged) cards. In-store, the transaction runs on Interac. Online or in-app, where Interac acceptance is more limited, the same card typically runs over the Visa or Mastercard network as Visa Debit or Debit Mastercard instead.

That routing switch changes the economics. Online debit transactions on the Visa/Mastercard rails are priced more like credit — a percentage-based fee, though generally at lower interchange rates than credit cards. So a merchant whose in-store debit costs pennies per transaction may pay a percentage when the same customer orders from their website. If you sell both in-person and online, your "debit" is really two different products with two different cost structures, and your statement should be read that way.

How to read your debit/credit mix on your statement

Your monthly processing statement almost always contains the numbers you need, even if it buries them. Here is what to pull out:

• Total Interac debit volume and total debit transaction count — divide fees charged on debit by the count to get your true cost per debit transaction
• Total credit volume by card type if available (standard, rewards, premium, corporate) — premium and corporate cards carry the highest interchange
• Your debit share: debit volume divided by total volume, and separately, debit transactions divided by total transactions
• Any line items for contactless/Interac Flash priced differently from chip-and-PIN debit
• Online (card-not-present) debit shown as Visa Debit or Debit Mastercard — these are percentage-priced and should not be lumped in with in-store Interac

Rules of thumb for choosing a pricing model

There is no single right answer, but the decision is less mysterious than processors make it sound:

• If more than half your in-store volume is Interac debit, a blended flat rate is almost certainly costing you money — insist on pricing with a flat per-transaction debit fee
• If your average ticket is high, percentage-based pricing on debit hurts more — a flat debit fee on a $200 sale is a rounding error; a percentage is not
• If you are mostly online, in-store Interac economics barely apply to you — focus on your credit and Visa Debit/Debit Mastercard rates instead
• Whatever the model, ask for the markup above cost in writing — a processor that won't separate its margin from network costs is telling you something

Run your own numbers

The fastest way to see what your mix is costing you is to put real numbers through it. Our savings calculator on the homepage (/#savings-calculator) lets you plug in your volume and see the difference between pricing models, and our pricing page (/pricing) shows how we structure debit and credit separately instead of blending them.

If your last statement doesn't clearly show a flat per-transaction cost on your Interac debit sales, that is the first question to ask — of your current processor, or of us.