For most established businesses, interchange-plus is the cheapest of the three pricing models, often by thousands of dollars a year. Flat-rate wins only at very low volume, where its simplicity outweighs its markup. Tiered almost always costs the most, because it is built to hide what you pay.
The catch with interchange-plus vs. flat-rate vs. tiered pricing is that the marketing for all three quotes you a percentage, and percentages hide dollars. So we are going to run the same business through all three and show you the actual money.
Interchange-plus charges wholesale cost plus a fixed, visible markup. Flat-rate charges one blended rate on every card and keeps the gap above wholesale. Tiered sorts your cards into “qualified” and “non-qualified” buckets you do not control. On a $30,000/month business, the spread between the cheapest and the most expensive is commonly $2,000 to $3,600 a year.
Interchange-plus vs. flat-rate vs. tiered: what is the difference?
All three start from the same wholesale cost: interchange (set by Visa and Mastercard, paid to your customer's bank) plus assessments (paid to the networks). We cover that foundation in credit card processing fees explained. The models differ only in how the processor adds its markup on top.
Interchange-plus pricing
You pay the exact wholesale cost, passed straight through, plus a clearly stated markup. A typical quote looks like “interchange plus 0.30% and 10 cents per transaction.” Your statement shows wholesale and markup as separate numbers, so you can see precisely what the processor earns. When wholesale rates drop, your cost drops with them. This is the model we build accounts on.
Flat-rate pricing
You pay one rate on every card, such as 2.6% plus 15 cents in person, regardless of whether the customer hands you a cheap debit card or a premium rewards card. It is simple and predictable, which is its real selling point. The downside is invisible: the processor keeps the entire difference between that flat rate and the true wholesale cost, and on debit that difference is large.
Tiered pricing
You are quoted a low “qualified” rate, then your transactions get sorted into qualified, mid-qualified, and non-qualified buckets at higher rates. The problem is that you do not decide which bucket a card lands in. The processor does. Rewards cards, business cards, and keyed-in sales routinely “downgrade” to the pricey tiers, so the rate you were sold is rarely the rate you pay.
What do they cost on the same $30,000/month business?
Take a business running $30,000 a month in card sales, average ticket $40, so about 750 transactions, with a normal debit-and-credit mix. The numbers below are illustrative and meant to show the structure and the gaps, not a quote.
| Pricing model | How you are charged | Monthly cost | Effective rate | Yearly cost |
|---|---|---|---|---|
| Interchange-plus | Wholesale + 0.30% + $0.10/txn | ~$705 | ~2.35% | ~$8,460 |
| Flat-rate | 2.6% + 15¢ on everything | ~$893 | ~2.98% | ~$10,710 |
| Tiered | Qualified/mid/non-qualified buckets | ~$1,010 | ~3.37% | ~$12,120 |
Same sales, same customers, same swipes. The only variable is the markup model. Interchange-plus runs about $2,250 a year cheaper than flat-rate here, and roughly $3,660 cheaper than tiered. That difference is not a rounding error. For a lot of small businesses, it is a month of rent.
One factor moves the gap more than any other: how much debit you take. Debit from large banks is rate-capped by federal law at 0.05% plus about 21 cents per transaction, under the Federal Reserve's Regulation II. Interchange-plus passes that low cost straight through to you. Flat-rate and tiered charge a full percentage on it anyway and keep the difference. If your sales skew toward debit, the dollar gaps above understate what you would actually save.
How does tiered hide the markup?
Tiered deserves a closer look, because it is the one most likely to surprise you. Say you are quoted 1.79% “qualified.” Here is what actually happens across a month:
- A basic card-present debit sale qualifies. You pay near the 1.79% you were promised.
- A customer pays with a cash-back rewards card. It downgrades to mid-qualified, maybe 2.4%.
- A phone or online order, or a business card, drops to non-qualified, often 3.3% or more.
Because most consumers now carry rewards cards, the bulk of your volume never sees the qualified rate. The headline number was real for a sliver of your sales and irrelevant for the rest. That is the design, not a glitch.
At what monthly volume does interchange-plus beat flat-rate?
Flat-rate is not a scam. At low volume it can genuinely be the better deal, because it usually carries no monthly fees and comes with free software. When you are running a few thousand dollars a month, paying a small markup for zero hassle is a fair trade.
The math turns as you grow. In our example, the per-dollar gap between flat-rate and interchange-plus is about 0.6%. Watch how that compounds:
| Monthly card volume | Flat-rate premium vs. interchange-plus | Per year |
|---|---|---|
| $5,000 | ~$31 | ~$375 |
| $10,000 | ~$63 | ~$750 |
| $15,000 | ~$94 | ~$1,125 |
| $30,000 | ~$188 | ~$2,250 |
| $50,000 | ~$313 | ~$3,750 |
The crossover usually lands somewhere between $5,000 and $15,000 a month, depending on your ticket size and the monthly fees on the interchange-plus plan. Below that, flat-rate's no-fee simplicity can win. Above it, you are paying a convenience tax that grows every month you stay. By $30,000 a month, that tax is real money, and it only gets larger.
Smaller tickets make the gap worse, not better, because per-transaction fees eat a bigger share of a $12 sale than a $120 one. If you run a café, a coffee shop, or any low-ticket business, the flat-rate premium hits you harder than the table above suggests. We break that down in the hidden cost of “free” and flat-rate POS.
When does flat-rate actually make sense?
Be honest with yourself about your stage. Flat-rate is a reasonable choice if you are brand new and processing very little, if your sales are tiny and sporadic, or if you sell occasionally and value zero monthly commitment over saving a few dollars. There is nothing wrong with paying for simplicity when the dollars are small.
It stops making sense the moment your volume is steady and meaningful. If cards are a core part of your revenue and you are past roughly $10,000 to $15,000 a month, the simplicity is no longer free. It is one of your larger controllable expenses.
Which model should you choose?
For most businesses with consistent volume, interchange-plus is the most transparent and usually the cheapest, because you only pay wholesale plus a markup you can see. Tiered is the one to avoid, since you cannot audit or control the buckets. Flat-rate is fine while you are small and simple.
There is no single rate that fits every business, which is the straight answer most processors avoid. The right markup depends on your monthly volume, your average ticket, your industry, and how much of your mix is debit versus rewards credit. We price each account to that profile rather than forcing you onto one number, and we will show you the wholesale and the markup separately so you can check our work.
The first step is knowing your current effective rate. Pull your latest statement (here is how to read it), find your total fees divided by total sales, and compare it to the interchange-plus column above.
When you are ready, get a free rate review and we will show you which model you are actually on, what it is costing you, and whether interchange-plus would beat it. If it would not, the numbers will make that clear.
Frequently asked questions
Is interchange-plus always the cheapest option?
For businesses with steady volume, almost always, because you pay wholesale plus a visible markup. At very low volume, flat-rate's lack of monthly fees can make it cheaper. The crossover is usually in the $5,000 to $15,000 a month range.
Why is tiered pricing considered the worst model?
Because you cannot control or audit which “tier” each card falls into. The low rate you are quoted applies to a fraction of your sales, while most transactions downgrade to higher buckets you never see coming.
What is a typical interchange-plus markup?
Markups vary by business, but competitive small-business pricing is often in the range of 0.20% to 0.50% plus a small per-transaction fee. The key is that it is stated and visible, not blended into one rate.
Can I negotiate my pricing model?
Yes. The pricing model and the markup are both negotiable, unlike wholesale interchange. Knowing your effective rate and your volume is your bargaining power.
Related reading: Credit card processing fees explained · How to read your merchant statement · The hidden cost of “free” and flat-rate POS