Interchange-Plus vs Blended Pricing: When Each Wins and What You Pay

The pricing model your PSP uses is not neutral. It decides whether the margin between what you pay and what your PSP earns is visible, negotiable, and benchmarkable — or buried in a single number that neither side discusses.

Blended pricing and interchange-plus (IC+) are the two dominant models for card acceptance pricing. Both pay the same underlying costs — interchange to the issuing bank, scheme fees to Visa or Mastercard, acquirer margin to your PSP. The difference is in how those costs are presented, which determines what you can see, what you can negotiate, and whether switching PSPs is easy or expensive.

What Blended Pricing Actually Is

Blended pricing presents a single flat rate — Stripe's standard US rate of 2.9% + $0.30, Square's US card-present rate of 2.6% + $0.15 (Square raised the flat fee from $0.10 in an October 2025 pricing update), and similar from most entry-level PSPs. The rate applies regardless of card type: the merchant pays the same whether the customer uses a basic debit card, a premium rewards credit card, or a corporate purchasing card.

A note on reading these figures: vendor pricing pages localise silently by IP address or cookie. The same stripe.com/pricing URL returns Singapore rates (3.4% + $0.50) by default and US rates (2.9% + $0.30) only when a US locale signal — like a country=US cookie — is present. Every rate in this article is labelled with the country its rate card belongs to; if you're re-checking any of these figures yourself in a plain browser, confirm which country's page you're actually looking at before comparing numbers.

The mechanism that makes this work for the PSP: on low-interchange cards (standard debit, EU consumer credit regulated at 0.20–0.30%), the PSP keeps the difference between the blended rate and the actual underlying cost. On high-interchange cards (premium rewards, corporate, commercial), the PSP absorbs the cost from the low-interchange margin it built up elsewhere. Across a large enough merchant base, the cross-subsidy works.

For an individual merchant, the economics depend on your card mix. Consider a US merchant on 2.9% blended pricing:

• A standard debit card transaction carries roughly 0.05% + $0.22 interchange (regulated under Durbin for large issuers). On a $100 transaction, the PSP collects $2.90, pays ~$0.27 in interchange, and keeps ~$2.63 plus scheme fees. Effective PSP margin: ~2.30%.
• A premium rewards credit card carries meaningfully higher interchange than standard debit — the exact rate varies by card tier and merchant category and is not a single published number, so treat any flat "X%" rewards-card figure as an approximation rather than a market rate. Because the PSP still collects the same $2.90 blended rate but pays out more in interchange on these transactions, its effective margin on rewards-card volume is thinner than on debit-card volume — potentially much thinner, depending on where the specific card and category land.

The same blended rate, opposite economics depending on which card your customer pulls out. At 2.9%, a debit-heavy merchant is significantly overpaying relative to their actual interchange cost.

What Interchange-Plus Looks Like

Under IC+ pricing, interchange and scheme fees pass through at cost. Your statement shows the actual interchange each transaction incurred, the scheme fees charged by Visa and Mastercard, and the acquirer margin separately. The margin is what your PSP actually earns.

A typical IC+ contract reads: interchange at cost + 0.20% + $0.10 per transaction. On that same $100 standard debit transaction:

• Interchange: $0.27 (at cost)
• Scheme fees: ~$0.10
• Acquirer margin: 0.20% + $0.10 = $0.30
• Total: $0.67 — versus $2.90 blended

On a premium rewards credit card, the same structure applies but interchange is meaningfully higher — again, the exact rate depends on card tier and merchant category rather than a single flat number — so the total lands well above the debit example while the acquirer margin (the $0.30 "plus") stays the same. That's the mechanical point IC+ makes visible: the acquirer margin doesn't move with card type, only the interchange pass-through does.

The IC+ rate is lower for debit-heavy merchants, higher-cost for premium-credit-heavy merchants, and always transparent about what goes where.

The Real Calculation: What Is Your Theoretical IC+ Cost?

Before deciding whether to push for IC+ pricing, you need an estimate of your actual interchange cost. This requires knowing your card mix — the distribution of card types across your transactions.

The rough calculation:

1. Estimate your blended interchange rate. Take your transaction volume by card type if your PSP reports it. Multiply each segment by the applicable interchange rate for your geography. For US merchants without this data, a reasonable starting estimate for an e-commerce business with a mixed consumer card base is 1.4–1.8% blended interchange.

2. Estimate scheme fees. For a typical US e-commerce merchant with minimal cross-border volume, scheme fees run 0.10–0.20% of volume.

3. Estimate achievable acquirer margin. No PSP publishes acquirer margin by volume tier. The one public data point available is Adyen's own indicative pricing — Interchange+ plus a published ~0.60% acquirer margin — which is a useful anchor precisely because it's vendor-stated rather than estimated. Beyond that anchor, treat any margin figure you're quoted as a negotiated number specific to your deal, not a market rate.

4. Sum the components. Interchange (1.4–1.8%) + scheme fees (0.10–0.20%) + your quoted acquirer margin = your estimated IC+ cost. Use a live quote for the third term rather than a published range — none exists — and compare the sum against your current blended rate.

Compare that against your current blended rate. If the gap is 0.50% or more, multiply it by your own annual card volume — no published threshold determines whether the result is worth pursuing, only what that number means for your business — and if it's meaningful relative to your margins, the negotiation is worth starting.

When Blended Pricing Is Defensible

Blended pricing is not always the wrong choice. Three scenarios where it may be rational:

Low volume with debit-heavy mix. At low monthly volume, IC+ may not be offered at all — no PSP publishes the floor at which it becomes available, so ask rather than assume you're below it — and the administrative complexity of tracking interchange categories may not be worth it relative to the savings involved. The blended rate is also partially a subsidy — PSPs price their small-merchant offering at a level that covers customer support, dispute handling, and account maintenance that is not volume-proportional.

Predictability over optimisation. For some operators, the variance in IC+ billing creates reconciliation complexity that costs more in staff time than the savings. A single blended rate is easy to forecast and integrate into pricing models.

Premium-card-heavy customer base. If your customers are disproportionately corporate or commercial card users — common in B2B SaaS — your interchange cost is not regulated at all: in the EU/UK, the consumer-card caps (0.20% debit / 0.30% credit) apply only to consumer cards, and commercial/corporate cards are explicitly excluded from the cap and priced by the issuer and network at whatever rate they set, typically well above the consumer bands. That makes B2B SaaS and similar corporate-card-heavy businesses the segment most exposed to uncapped interchange, not a segment that benefits from a subsidy by default. Premium rewards consumer cards are a different, smaller step up — they remain inside the regulated consumer caps in the EU/UK, unlike genuinely corporate/commercial cards. Whether blended pricing is cheaper than IC+ for a corporate-card-heavy merchant depends on whether your PSP's blended rate was priced assuming a lower-cost mix than you actually have; verifying your actual card mix against your blended rate is the only way to know, and for many B2B SaaS operators the honest answer is that uncapped commercial interchange makes seeing the real cost through IC+ more important, not less.

When IC+ Is Clearly Better

IC+ wins when the calculation above shows a gap of 0.50% or more, when you have volume to negotiate meaningful acquirer margin compression, or when you need to accurately model the per-transaction cost of acceptance by card type for pricing or routing decisions.

IC+ also wins in cross-border contexts. When interchange varies significantly by geography and by card category — EU consumer credit capped at 0.30% versus uncapped US premium and commercial cards that can run several times higher — blended pricing either overcharges your EU customers' card acceptance or forces you to accept unprofitable US premium-card economics depending on how the PSP structured the rate. IC+ lets you see and model both, which matters more than it looks: regulated caps like the EU's rarely cover the whole card mix an operator actually processes — see interchange regulation by market for where commercial cards, cross-border transactions, and specific card types fall outside the cap in each regime.

The final argument for IC+: it makes PSP comparisons precise. Comparing two blended rates requires you to know that the card mix assumption behind each rate is identical — which it rarely is. Under IC+, you can compare acquirer margin directly across PSPs because the interchange and scheme components are identical. It converts a complex multi-variable comparison into a single negotiable number.

How to Push for IC+ Pricing

Most PSPs offer IC+ only above some volume threshold, but none of the three major providers checked here — Stripe, Checkout.com, or Adyen — publishes what that threshold is; their live pricing pages say only "contact sales" or that eligibility varies by market. Adyen is the exception worth flagging: its own pricing page openly publishes an indicative Interchange+ + 0.60% acquirer margin, which is the one genuinely vendor-sourced IC+ figure available without a sales call — but even Adyen doesn't state a volume floor for who gets access to it.

The conversation framework:

1. Request an itemised processing statement for the last 90 days showing interchange, scheme fees, and acquirer margin as separate line items. If the PSP provides this on request, you already have IC+ reporting — ask to convert the contract to IC+ pricing formally.
2. Calculate your blended interchange from that statement. Use this as your anchor in the pricing conversation.
3. Quote your total volume, card mix, and chargeback ratio as context for the margin offer. PSPs price IC+ acquirer margin primarily on volume and risk, not negotiating skill.
4. Benchmark against published IC+ margins at comparable PSPs. Adyen publishes an indicative acquirer margin of Interchange+ plus roughly 0.60% on its own pricing page — the one genuinely vendor-sourced IC+ benchmark available without a sales call. Use it as an anchor, not a universal rate; your own quote will vary by risk profile and volume.

The acquirer margin under IC+ is the most negotiable component of card acceptance costs — and IC+ pricing is the only way to see it clearly enough to negotiate it.

The Comparison Problem

A persistent practical issue: most operators compare PSPs on headline blended rates without understanding that the rates are not directly comparable. A 2.7% blended rate at PSP A versus a 2.9% blended rate at PSP B may be cheaper or more expensive depending on your card mix and how each PSP priced for their expected customer base.

The only clean comparison methodology:

1. Run the same transaction volume through a theoretical IC+ model using your actual card mix.
2. Get IC+ quotes from each PSP.
3. Compare the acquirer margin component — that is the only variable that differs between PSPs. The interchange and scheme fee components are identical.

Blended pricing makes this comparison impossible by design. That is not necessarily intentional obfuscation — it is a pricing model built for simplicity — but the effect is that operators who accept blended pricing cannot accurately compare their PSP to alternatives. IC+ pricing, whatever its complexity, is the model that enables informed vendor decisions.

The headline rate is not the fee. It is the summary of four layers, one of which is fixed, one semi-fixed, one negotiable, and one often invisible. Knowing which is which is the prerequisite to paying less of all four.