field notes 2026-04-18 8 min read the multiflow desk

Free interchange-plus breakdown calculator

3-minute scan
  • Interchange+ breakdown Enter volume and mix.
  • Calculator estimates true interchange, assessments, and processor markup separately.
  • Of the three, only IC+ lets you see what's actually happening.
On this page

    Interchange+ breakdown

    Enter volume and mix. Calculator estimates true interchange, assessments, and processor markup separately.

    (function(){ function calc(){ var vol = parseFloat(document.getElementById("ip-vol").value)||0; var ticket = parseFloat(document.getElementById("ip-ticket").value)||50; var eff = parseFloat(document.getElementById("ip-eff").value)/100; var rewPct = parseFloat(document.getElementById("ip-rewards").value)/100; var bizPct = parseFloat(document.getElementById("ip-biz").value)/100; var intlPct = parseFloat(document.getElementById("ip-intl").value)/100; var regulatedPct = Math.max(0, 1 - rewPct - bizPct - intlPct); // Estimate blended interchange var icRew = 0.0180, icBiz = 0.0265, icIntl = 0.0290, icReg = 0.00155; // approximations for CNP var icPerTxnFix = 0.10; var blendIc = regulatedPct*icReg + rewPct*icRew + bizPct*icBiz + intlPct*icIntl; var txns = vol / ticket; var icFixed = (txns * icPerTxnFix) / vol; var totalIc = blendIc + icFixed; var assess = 0.00143; // Visa 0.14% + Mastercard 0.1375% blended, NABU/APF fixed fees estimated separately var totalFees = vol * eff; var totalIcDollars = vol * totalIc; var totalAssessDollars = vol * assess; var markupDollars = totalFees - totalIcDollars - totalAssessDollars; var markupRate = markupDollars / vol; var html = '
    Total monthly processing cost
    $'+Math.round(totalFees).toLocaleString()+'
    At '+(eff*100).toFixed(2)+'% effective
    '; var rows = [ {label:"Interchange (to issuer banks)", value:totalIcDollars, rate:totalIc, neg:"Not negotiable — set by networks", color:"#8a9bb4"}, {label:"Assessments (to networks)", value:totalAssessDollars, rate:assess, neg:"Not negotiable — set by Visa/MC", color:"#8a9bb4"}, {label:"Processor markup", value:markupDollars, rate:markupRate, neg:"Fully negotiable", color:markupRate > 0.008 ? "#ff5a5a" : markupRate > 0.004 ? "#ffa940" : "#52c41a"} ]; rows.forEach(function(r){ var pct = ((r.value / totalFees)*100).toFixed(1); html += '
    '+r.label+'
    '+r.neg+'
    $'+Math.round(r.value).toLocaleString()+'
    '+(r.rate*100).toFixed(3)+'% ('+pct+'% of total)
    '; }); html += '
    Note: Interchange figures are US CNP category averages. Your real bill will vary ±10-20 bps based on card mix precision and per-transaction fixed fees.
    '; document.getElementById("ip-result").innerHTML = html; } document.getElementById("ip-calc").addEventListener("click", calc); calc(); })();

    Why interchange-plus is the only honest pricing model

    Most merchants pay one of three pricing models: flat rate (2.9% + 30¢ Stripe-style), tiered (qualified / mid / non-qualified), or interchange-plus (IC+). Of the three, only IC+ lets you see what's actually happening. The other two are abstractions that hide where the money goes.

    On IC+ pricing, your processor discloses the true interchange cost per transaction (what the issuer bank takes), the network assessments (what Visa and Mastercard take), and adds a fixed markup on top. The markup is the processor's revenue — and it's the only part of the bill that's actually negotiable.

    On flat-rate pricing, you pay a fixed percentage that's set high enough to absorb any card mix. The processor keeps whatever's left over after interchange. On a card with cheap interchange (basic debit at 0.05% + 22¢) the processor keeps 2.75%. On an expensive card (premium rewards at 2.4%) they keep 0.5%. You have no visibility into which transactions are profitable for the processor and which ones aren't.

    On tiered pricing, the processor buckets transactions into "qualified" (cheap interchange), "mid-qualified" (medium), and "non-qualified" (expensive). The tier definitions are opaque and processor-defined. The markup in each tier is not disclosed. It's the most obscured model and almost always the most expensive.

    What the calculator actually does

    Enter your monthly volume, average ticket, current effective rate, and card mix. The calculator estimates what interchange + assessments cost on that mix (using US CNP category averages published by Visa and Mastercard), then backs out the markup your processor is keeping.

    The markup number is the important one. A healthy processor markup for a $500k/mo merchant on clean ecommerce is 15-30 basis points. Above 60 bps, you're overpaying. Above 100 bps, your processor is profit-dumping on you and you should start shopping.

    The components in detail

    Interchange

    Set by the card networks and paid to the issuing bank (the customer's bank that issued their credit card). Interchange rates vary by card type, transaction type, and merchant category. Visa alone has 300+ distinct interchange rates. Key ranges:

    • Regulated debit (Durbin): 0.05% + 22¢ — the cheapest category
    • Unregulated debit / basic credit: 1.4-1.8%
    • Rewards credit: 1.6-2.0%
    • Premium/business credit: 2.2-2.7%
    • International: 1.8-2.9% plus cross-border fees

    You cannot negotiate interchange. It is the cost of goods sold in payments.

    Assessments

    Small per-transaction fees the networks charge on top of interchange for running the network. Visa assesses 0.14% of every transaction. Mastercard assesses 0.1375%. American Express, Discover, and Amex OptBlue set their own. Also not negotiable.

    Networks also impose fixed per-transaction assessments (Visa's NABU at 1.95¢, Mastercard's NABU at 2¢, APF and similar). These are cents per transaction and matter disproportionately for low-ticket merchants.

    Processor markup

    This is what your processor keeps. On IC+ pricing it's clearly disclosed (e.g., "IC + 0.25% + 10¢"). On tiered or flat-rate it's buried. It covers the processor's infrastructure, sales acquisition cost, dispute handling, and profit margin. It is 100% negotiable for any merchant at or above $100k/mo.

    What "good markup" looks like by volume

    Under $100k/mo: 30-50 bps plus 10-20¢ per transaction. You don't have much leverage.

    $100k-500k/mo: 20-35 bps plus 8-15¢. Negotiate annually.

    $500k-2M/mo: 12-25 bps plus 6-12¢. Multiple processor quotes required.

    $2M-10M/mo: 8-18 bps plus 5-10¢. Direct acquirer relationships possible.

    $10M+/mo: 5-12 bps plus 3-8¢. Enterprise pricing. Adyen, Worldpay direct, Chase Paymentech ranges.

    High-risk markup reality

    High-risk verticals (CBD, peptides, nutra, adult, kratom) pay 2-5x the markup of low-risk merchants for the same volume. A $500k/mo CBD merchant pays 80-150 bps markup where a $500k/mo dropshipper pays 20-30 bps. This reflects risk pricing, not infrastructure cost. It is negotiable but the floor is higher.

    Multi-brand portfolio markup compression

    When 8 brands run on 8 separate processor accounts, each brand negotiates alone. Each pays small-merchant markup. Aggregate markup across the portfolio is 60-90 bps.

    When the same 8 brands consolidate under a parent merchant account via multiflow, the parent's aggregated volume qualifies for mid/large-merchant markup (15-30 bps). Passing that through to sub-brands with our platform fee on top, the effective blended markup is typically 35-55 bps — 20-40 bps less than running separately.

    FAQ

    Can I see my actual interchange cost?

    Only on IC+ pricing. Your processor's monthly statement itemizes interchange category, count, and cost on that pricing model. On flat-rate or tiered, it's not disclosed.

    Is interchange higher for online vs in-person?

    Yes. Card-not-present interchange is 20-60 bps higher than card-present on the same card type because CNP fraud risk is higher.

    Why does international volume cost more?

    Three stacked fees: higher interchange on foreign cards, cross-border fee (0.8-1.0% added), and currency conversion fee if you settle in a different currency. See our cross-border fee estimator.

    Should I switch from flat-rate to IC+?

    Above $50k/mo, almost always yes. Below $50k/mo the math favors flat-rate because the per-transaction fees on IC+ bite harder on small volume.

    Can Stripe offer IC+ pricing?

    Yes, at scale. Stripe's "Custom" pricing for $500k/mo+ merchants is effectively IC+. You need to ask for it explicitly; the default Stripe contract is flat-rate.

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