A small change in payment processing costs is creating a bigger concern for some Canadian retailers. Effective November 1, 2026, certain auto-parts and home-supply merchants face a 75% increase in the interchange fee charged on eligible Interac contactless debit transactions.
The adjustment raises the affected fee from two cents to 3.5 cents per transaction. Although the difference is just 1.5 cents per payment, the additional expense can accumulate for businesses handling thousands of purchases every month.
The increase also highlights an important distinction between wholesale payment-network charges and the total processing fees merchants actually pay. As businesses navigate higher operating expenses and changing consumer payment habits, understanding precisely where these costs arise has become increasingly important.
The 75% Increase Targets a Specific Debit Fee
The headline figure comes from a specific change to Interac Flash interchange rather than an across-the-board increase in debit processing charges. In its November 2026 fee notice, Moneris confirms that merchants classified under Merchant Category Code (MCC) 5531 who previously qualified for Tier 1 pricing are being moved to Tier 3. The change applies to eligible contactless debit purchases valued between one cent and $100. Their interchange rate rises from $0.020 to $0.035 per transaction, effective November 1.
For affected retailers, the change happens behind the scenes. A customer purchasing a $12 windshield wiper or a $65 household tool can complete the same familiar tap, but the economics of that transaction have changed. Importantly, this is not a universal 75% increase for every business accepting debit cards. The adjustment concerns a particular merchant category and transaction type. How much additional expense reaches an individual retailer ultimately depends on its agreement with its payment processor.
A Four-Digit Merchant Code Determines Which Businesses Are Affected
The distinction between an affected and unaffected retailer may come down to four digits. MCC 5531 identifies businesses selling a mixture of automotive and home-improvement merchandise. Mastercard’s merchant classification guidance describes this category as covering retailers offering products such as automobile parts, tires, batteries, household appliances and repair supplies. These stores may serve customers working on vehicles and home-improvement projects under the same roof.
However, not every automotive or hardware business belongs to this category. Dedicated automotive parts and accessories stores can be classified under MCC 5533, while automotive tire stores have MCC 5532. Home-supply warehouses and hardware stores also have separate classifications. That difference matters because Moneris specifically identifies MCC 5531 in its November 2026 adjustment. A specialized parts retailer should not assume that the same change applies simply because it sells automotive products. The merchant’s assigned code, rather than its storefront description or advertising, is the important starting point for determining whether it is affected.
The New Pricing Reverses a Discount Introduced in 2024
The November 2026 adjustment becomes more significant when viewed alongside an earlier change. On November 1, 2024, Interac introduced lower Flash interchange rates for several merchant categories, including MCC 5531. Qualifying businesses moved from Tier 3 pricing of 3.5 cents to Tier 1 pricing of two cents for applicable contactless transactions. That represented a reduction of approximately 42.9% in the interchange fee, giving participating merchants a modest break on each eligible payment.
Two years later, the newly announced adjustment reverses that benefit for the specified home-and-auto category. The return to 3.5 cents does not establish that every retailer’s total processing bill will return to its previous level, because other fees and merchant contracts may have changed. Nevertheless, it removes the earlier interchange advantage. The broader 2024 discount program also included businesses such as car washes, electric-vehicle charging providers and passenger transportation operators. Moneris’s November 2026 reclassification notice specifically names MCC 5531, so businesses in those other categories should not assume their discounted interchange rates have been withdrawn.
Why an Extra 1.5 Cents Can Become a Meaningful Expense
An additional 1.5 cents sounds almost insignificant when considering a single purchase. The calculation changes when a business processes large numbers of transactions. At 1,000 affected debit taps, the added interchange amounts to $15. At 5,000 transactions, it reaches $75. A merchant processing 10,000 eligible taps would see $150 in additional interchange charges, assuming the entire increase is passed through. These calculations exclude the separate costs charged by payment processors.
Consider a retailer with several busy locations selling automotive fluids, replacement parts and household supplies. Even modest increases across regular purchases can accumulate throughout the year. At 10,000 eligible transactions per month, the theoretical annual increase would reach $1,800 if that volume remained constant. The key variable is the number of qualifying transactions, not the total dollar value of merchandise sold. This makes the adjustment especially relevant to higher-traffic businesses, even though the additional fee on any individual purchase remains small.
Transaction Size Makes a Difference to the New Charges
Not every debit purchase at an affected retailer carries the same interchange fee. Interac’s published structure divides contactless transactions into different pricing categories. For purchases between $0.01 and $100, the merchant’s classification helps determine whether a two-cent, 2.5-cent or 3.5-cent rate applies. However, contactless transactions valued between $100.01 and $250 carry a separate interchange fee of 5.5 cents for all merchants. The November reclassification does not increase that particular rate.
Payment method also matters. Standard chip-and-PIN Interac debit transactions carry zero interchange, although other processing and network charges may still apply. This distinction is relevant at an automotive supply counter, where customers might purchase a $25 bulb, a $95 battery or a $175 toolkit. Each purchase could have different processing characteristics depending on how the customer pays. Interac contactless transactions generally have a maximum value of $250, subject to financial institution limits. Consequently, the new pricing does not apply uniformly to every debit purchase made inside an affected store.
The 75% Increase Does Not Mean Total Processing Bills Rise 75%
Interchange represents only one component of what merchants pay to accept electronic payments. Payment processing costs may also include network assessment charges, processor markups and charges associated with payment equipment or related services. Interac explains that its acquirer processing fees vary according to agreements between merchants and their providers. As a result, the newly announced 3.5-cent interchange rate should not be confused with the full price of accepting a debit transaction.
Different payment companies also use different pricing structures. Helcim describes an interchange-plus model that separates wholesale network charges from its own processing margin. Square, meanwhile, publicly lists a standard Canadian in-person debit processing fee of 0.75% plus seven cents per transaction. Those differences help explain why merchants may experience network changes differently. A retailer with interchange-plus pricing could see the additional charge reflected more directly, while a merchant on an inclusive or flat-rate arrangement might see no immediate adjustment to its published transaction rate. The actual financial impact depends on the payment agreement and whether the provider passes the increase along.
Another Interac Fee Increase Arrived on November 1
The reclassification of home-and-auto merchants is not the only Interac-related pricing adjustment taking effect in November 2026. Moneris has also announced increases to Interac switch assessment and mobile service fees. Its published figures rise from $0.015803 to $0.016315 per applicable transaction. That represents an increase of approximately 3.2%, substantially smaller than the 75% increase affecting the specialized Flash interchange category. TD Merchant Solutions has separately disclosed a comparable November 1 assessment fee adjustment, using rounded figures of approximately 1.58 cents and 1.63 cents.
The distinction between these adjustments is important. Moneris says the higher switch assessment applies to card-present Interac Debit transactions, while its mobile service fee adjustment applies to contactless debit payments made using smartphones or other supported devices. The interchange reclassification, meanwhile, targets qualifying purchases at MCC 5531 merchants. For example, 10,000 transactions subject to the separate $0.000512 assessment increase would generate another $5.12 in charges if fully passed through. Merchants reviewing November statements should distinguish these different fees rather than combine their percentage increases into one misleading figure.
Canadians Are Using Contactless Payments More Frequently
Debit cards remain an important part of how Canadians pay for everyday purchases. Payments Canada’s October 2026 report examined 26.7 billion retail payment transactions completed during 2025. Debit cards represented approximately 25% of total payment volume, while credit and debit cards combined accounted for 68%. Contactless payment volume increased by 9% compared with the previous year. Interac’s own corporate reporting also recorded approximately seven billion Interac Debit transactions in 2025, including 1.8 billion transactions made through mobile devices.
These figures help explain why even relatively small adjustments to payment-processing expenses deserve attention. Contactless payment is no longer an unusual checkout option. For many Canadians, tapping a card or smartphone has become part of shopping for groceries, household supplies and other everyday necessities. Retailers benefit from the convenience and speed, but every electronic transaction has an associated cost structure. Importantly, national payment trends cannot determine what an individual store will pay. A business with limited qualifying debit-tap volume may experience only a minor increase, while one handling thousands of eligible purchases every month could see a more noticeable change.
Customers Will Not Automatically Pay More for Using Debit
The increase in merchant-side interchange fees does not automatically translate into an additional charge for shoppers. Interac maintains specific rules governing debit surcharges. Its published guidance states that merchants cannot directly impose a surcharge on cardholders for using the Interac Debit service. Where an applicable surcharge is permitted, it must be imposed through the acquirer, cannot exceed 25 cents, and must be properly disclosed. Customers must also have an opportunity to cancel the transaction without incurring that surcharge. The Financial Consumer Agency of Canada notes that most merchants do not charge additional debit fees.
Nevertheless, retailers must consider payment processing alongside their other operating expenses. A store might absorb the additional costs within existing margins, reconsider its overall pricing strategy or search for more competitive processing arrangements. These are possible business responses rather than confirmed consequences of the November increase. A customer purchasing an inexpensive replacement part or household accessory may notice no difference whatsoever at checkout. The important distinction is that a 75% increase in one interchange component does not mean a 75% increase in retail prices, total processing charges or the amount a consumer must pay.
Merchants Have Options for Reviewing and Challenging Their Fees
For affected businesses, the most practical response begins with understanding their own payment activity. Retailers can confirm their merchant category code, determine whether they previously qualified for Tier 1 Flash pricing and review the number of contactless Interac transactions valued at $100 or less. They can then calculate the additional interchange using the 1.5-cent difference. Separating interchange from switch assessment fees, processing markups and equipment charges produces a clearer picture of the financial impact. It also makes comparisons between payment providers more meaningful.
Canadian merchants have protections under the federal Code of Conduct for the Payment Card Industry in Canada. For applicable fee increases, processors generally must provide 30 to 60 calendar days’ advance notice, disclose the old and new amounts, and explain qualifying merchants’ rights to exit agreements without penalty within 70 calendar days after the change takes effect. Exceptions exist, including certain predetermined contractual fee schedules. Businesses disputing a charge should first contact their acquirer, with unresolved Code-related complaints eligible for escalation through the payment network. Although the increase may represent only pennies per transaction, understanding the charges and available protections can help retailers make informed decisions.
