Flat rate processing in Canada, honestly explained.

What flat rate processing actually is

Flat rate is exactly what it sounds like. You pay one rate on every credit card transaction. Same percentage. Every time. No matter what card the customer hands you.

Square charges 2.65% in person. Stripe charges 2.9% + $0.30 online. Toast restaurant processing is somewhere around 2.49% + $0.15. Each of those is a flat rate. The processor doesn't show you what they're paying in interchange. They just take their cut and call it a day.

That's the whole pitch — predictability. You know exactly what every transaction costs you. There's no statement to decode. No interchange downgrades to worry about. One rate, every time.

Flat rate caught on because it solved a real problem — old-school merchant statements were intentionally confusing, and processors used the complexity to overcharge. Square came along with "2.65%, that's it" and millions of merchants signed up. The trade-off most of them didn't realize they were making — they were now paying the same rate on a $0.40-interchange debit card as on a $1.85-interchange premium credit card.

How flat rate works behind the scenes

The mechanics are simple. Every credit card transaction has an underlying interchange cost — that's the fee Visa or Mastercard charges the bank that issued the card. Flat rate processors pay that interchange to the card networks just like everyone else. Then they charge you their flat rate. The spread between the two is their profit.

Look at that debit row. The actual interchange cost on a $50 debit transaction is about $0.025. Flat rate charges you 2.65% of $50 — which is $1.32. Square pockets the difference. Roughly $1.30 of pure margin on one $50 swipe.

That's not Square being greedy — that's the model working as designed. The flat rate has to cover the most expensive transactions (premium credit cards) and still leave a margin. So they price the rate above where it needs to be on the cheap transactions to make the math work overall.

Typical flat rates in Canada

Here's where flat rate sits across the major Canadian processors in 2026. These are headline rates — there are usually extra fees (chargebacks, refunds, currency conversion) layered on top.

Worth knowing — Helcim's "flat rate" above a $25K monthly threshold isn't a true flat rate. It's actually an Interchange Plus rate they call flat rate for marketing simplicity. Same for some of Stripe's higher-volume tiers. The pure flat-rate players are Square, PayPal, Shopify Payments, and Dough's flat rate option.

For a deeper comparison on the biggest flat rate processor in Canada, read Dough vs Square or Dough vs Stripe.

The math: what flat rate actually costs you

Let's run real numbers across three typical Canadian small businesses. All three on Square at 2.65% in person.

Retail boutique — $20K/month, mostly debit and standard credit

A small clothing boutique processes $20,000 a month. Card mix is roughly 40% debit, 50% standard credit, 10% rewards. Average ticket is $65.

Restaurant — $50K/month, heavy debit and Interac

A neighbourhood café running $50,000 a month. Tons of small transactions. Card mix is about 55% debit, 35% standard credit, 10% rewards. Average ticket around $18.

Service business — $30K/month, mixed cards

A salon doing $30,000 a month. Card mix is about 30% debit, 50% standard credit, 20% rewards. Average ticket $85.

That salon could earn back a Boost Pro tier free website, a year of social media content, and still have thousands left over — just by moving off flat rate. Read the Boost program page for what those perks look like.

Flat rate vs Interchange Plus

This is the most important comparison if you're currently on Square or Stripe and wondering whether to switch.

The trade-off is real but lopsided. Flat rate gives you simplicity. IC+ gives you transparency and lower fees. For most established businesses, the savings on IC+ are way more valuable than the simplicity of flat rate. The IC+ guide walks through the full breakdown.

Flat rate vs surcharging

If you qualify for surcharging — meaning you're not in Quebec and your business model can absorb a customer-facing fee — surcharging makes flat rate look ridiculous.

That's roughly $15,800 a year. Surcharging drops your credit card processing fees to $0 by passing the cost to the customer who chose to pay with credit. Read the surcharging guide for the full mechanics.

If you're in Quebec or your customer base won't tolerate a surcharge, dual pricing or a cash discount program gets you to the same financial outcome with different presentation.

Who flat rate actually fits

Flat rate isn't bad. It's just rarely the right model. Here's where it does fit.

Very low volume merchants (under $5K/month)

At very low volume, the difference between flat rate and IC+ in absolute dollars is small. A merchant processing $3,000 a month might save $30-$60 by moving to IC+. Not nothing — but the simplicity of flat rate may genuinely be worth it at that volume.

Brand new merchants with no history

If you have no processing statements, no card mix data, and no idea what your card mix will be, IC+ is harder to quote precisely. Flat rate gives you a predictable starting point. After three to six months of processing, you can switch to IC+ with real data.

Pop-up or seasonal businesses

If you only process for a few weekends a year — craft fairs, farmers' markets, seasonal events — flat rate's simplicity beats the marginal savings of IC+. Square and Stripe have nailed the pop-up use case.

Businesses that genuinely value predictability above all

Some owners want to know that this month's processing fee will be exactly 2.65% of revenue, no surprises, no audit, no fine print. If that's worth a few thousand a year to you, flat rate works. For most owners, it isn't.

When to leave flat rate

The clearest signs that flat rate is costing you more than it should.

1. You're processing more than $20K/month

Above this threshold, the savings on IC+ or surcharging almost always exceed $200 a month. Compounding annual savings, this is the threshold where flat rate becomes hard to defend.

2. Your card mix is debit-heavy

Retail, restaurants, salons, gas stations, convenience stores. Anywhere customers pay primarily with Interac or debit. Flat rate is charging you 2.65% on transactions that should cost 0.5%. The bigger your debit volume, the bigger the leak.

3. Your average ticket is over $200

Auto repair, trades, professional services, medical practices. At higher ticket sizes, surcharging works extra well — customers expect to pay full price and don't blink at a credit card fee. Surcharging drops your processing bill to $0 entirely.

4. You've never read your statement

If you couldn't tell me right now what you paid in processing fees last month, you're not auditing your spend. Flat rate is hiding what could be thousands a year. Read the merchant statement guide first, then quote IC+ or surcharging.

5. You're tired of Square's customer service

Or Stripe's account freezes. Or PayPal's holds. The big flat-rate processors are software companies first. They support hundreds of millions of merchants and rarely talk to any of them. If you want a real human who picks up the phone, that's a separate reason to look at Dough.

Dough's flat rate option

Dough offers flat rate as one of three pricing models — alongside Interchange Plus and surcharging — at 2.75% + $0.15 per transaction. It's offered for merchants who specifically want predictable pricing and don't qualify (or don't want) IC+ or surcharging.

Most Dough merchants don't pick flat rate. They pick IC+ or surcharging because the math works better. But the option is there for the cases where flat rate genuinely fits.

One advantage of Dough's flat rate over Square or Stripe — you still get the Boost program perks. Free websites, free social media, custom AI tools. Even at flat rate pricing, you're getting back business-growth value Square and Stripe don't offer.

Common mistakes with flat rate

The traps merchants fall into around this model.

1. Believing the headline rate is your effective rate

For true flat rate (Square, Stripe, PayPal, Shopify Payments) — yes, the headline rate is roughly your effective rate. For everything else, including most bank processors, the headline rate hides downgrades and extra fees. Always calculate your effective rate from your statement total.

2. Assuming flat rate is "the cheapest option for small businesses"

Small business doesn't mean low volume. A neighbourhood restaurant doing $50K a month is technically a small business — but they're processing enough that flat rate is bleeding them dry. Volume is what matters, not company size.

3. Ignoring the spread on debit transactions

This is the biggest hidden cost. Every debit swipe at 2.65% on a $0.025-interchange transaction is pure profit for your processor. The more debit you take, the worse flat rate gets.

4. Sticking with flat rate "because the statement is simpler"

An IC+ statement isn't harder to read once you understand it. It just looks longer. Spend 10 minutes with one and the format becomes clear. Trading $4,000 a year for "simpler statements" is a bad trade for most businesses.

5. Forgetting about Stripe's online rate

Stripe's 2.9% + $0.30 is brutal on small online transactions. A $10 online purchase costs you $0.59 in fees — almost 6% effective. If you're running CNP volume on Stripe, IC+ is going to be dramatically cheaper. See the full Stripe breakdown →