Interchange Plus vs Flat Rate in Canada (2026): What Merchants Actually Pay

Interchange-plus pricing separates wholesale network fees from the payment processor markup. Flat-rate pricing blends these fees into a single charge. When flat-rate providers apply fixed percentage rates across transactions, they absorb wholesale cost variations directly into their own margins.

Interac publishes wholesale debit rates in Canada, including Contactless Tier 1 fees as low as CA$0.02 per tap. Under percentage-based flat-rate pricing models, processors pocket these ultra-low wholesale interchange fees rather than passing the savings to the merchant.

By unbundling card network interchange from processor margins, interchange-plus models allow Canadian merchants to capture wholesale rates directly. This structural difference makes interchange-plus significantly cheaper across standard Canadian merchant transaction blends.

Comparing a payment processor like Helcim against Moneris Flat Rate Pricing illustrates the structural differences between these models. Helcim operates an interchange-plus model charging a card-present margin of 0.4% + CA$0.08 over wholesale rates, alongside a card-not-present margin of 0.5% + CA$0.25. In contrast, comparing Helcim vs Moneris reveals Moneris Flat Rate Pricing charges a fixed 2.65% + CA$0.10 for card-present credit, 2.85% + CA$0.30 for card-not-present credit, CA$0.12 for card-present Interac Debit, and CA$1 for card-not-present Interac Debit.

The primary difference lies in fee predictability versus overall cost efficiency. Moneris offers fixed transaction rates that simplify monthly bookkeeping, but charges higher rates on credit sales. Helcim passes the exact wholesale card network interchange directly through to the merchant while adding its published margin. This unbundled structure produces lower overall processing costs across typical Canadian sales volumes, establishing true parity between wholesale costs and merchant fees.

Processing costs for a Canadian merchant vary dramatically based on provider pricing structures and sales channels. We analyzed a business processing CA$10,000 per month with a CA$50 average sale across 200 monthly transactions (60% credit / 40% debit mix). Helcim Interchange Plus card-present processing costs CA$210 per month or CA$2,520 per year. This yields a 2.1% all-in effective rate based on a 1.54% average credit interchange plus its 0.4% + CA$0.08 markup. Under Moneris Flat Rate Pricing card-present, that same transaction mix costs CA$285 per month or CA$3,420 per year at a 2.85% all-in effective rate. Intuit QuickBooks Online Payments card-present costs CA$340 per month or CA$4,080 per year, resulting in a 3.4% all-in effective rate. For online sales at this volume, Helcim costs CA$254 per month (CA$3,048 per year, 2.54% effective rate) compared to Moneris Flat Rate online at CA$345 per month (CA$4,140 per year, 3.45% effective rate).

Costs scale proportionally at CA$25,000 per month in volume across 500 monthly transactions under the same CA$50 average sale and 60/40 mix. Helcim Interchange Plus card-present costs CA$525 per month or CA$6,300 per year, maintaining a 2.1% all-in effective rate. Moneris Flat Rate Pricing card-present reaches CA$712.50 per month or CA$8,550 per year at a 2.85% effective rate. QuickBooks Online Payments card-present reaches CA$850 per month or CA$10,200 per year at a 3.4% effective rate. In online channels at CA$25,000 monthly volume, Helcim costs CA$635 per month (CA$7,620 per year at a 2.54% effective rate) versus Moneris Flat Rate online at CA$862.50 per month (CA$10,350 per year at a 3.45% effective rate).

Wholesale card network rates set the baseline cost of payment processing before any payment processor adds its fee markup. Interac publishes wholesale debit interchange rates in Canada, including a Contactless Tier 1 low-ticket fee of CA$0.02 per transaction and an eCommerce Tier 1 rate of 0.6% capped at a maximum of CA$1.80. Credit network wholesale rates vary by card type. Visa's published Canadian rate card includes a Consumer Electronic rate for small merchants of 0.77%, alongside an Infinite Privilege card-not-present rate for small merchants of 2.3%.

Flat-rate pricing models charge a fixed fee—such as QuickBooks Online Payments at 2.9% + CA$0.25 per transaction—regardless of the underlying card type. On lower-cost cards like Visa Consumer Electronic at 0.77% interchange or Interac Contactless Tier 1 debit at CA$0.02, a flat 2.9% rate creates a substantial margin for the processor. The business pays a steep premium over wholesale costs on everyday low-cost transactions.

A competitive effective rate benchmark for a Canadian business processing a standard mix of 60% credit and 40% debit card volume ranges from 2.1% to 2.54% depending on sales channels. On an optimized interchange-plus setup like Helcim, businesses achieve an all-in card-present effective rate of 2.1% and an online effective rate of 2.54%.

Flat-rate pricing structures automatically elevate these cost baselines. Card-present flat-rate pricing yields effective rates between 2.85% with Moneris Flat Rate Pricing and 3.4% with QuickBooks Online Payments, while online flat-rate processing reaches 3.45% under Moneris. Establishing an effective rate near 2.1% for retail or 2.54% for e-commerce ensures that payment processing fees remain minimized.