Payment Methods May 21, 2026 · 6 min read

What Is Interchange? How Peptide Merchants Lower Processing Costs

Interchange is the wholesale fee Visa and Mastercard charge issuers — the largest line item in your peptide processing bill. Here is how to read it and reduce it.

By Evan Valenti
Quick answer

Interchange is the wholesale per-transaction fee the cardholder's bank charges your processor. It runs 1.5–2.5% on most peptide transactions and is the same at every processor — what differs is the markup on top. Switching from flat-rate to interchange-plus typically saves peptide merchants 0.6–1.1% effective rate.

How interchange works

Every Visa/Mastercard transaction has a published rate set by the network, depending on card type, transaction type, MCC, and whether 3DS was used. A typical card-not-present rewards Visa runs 2.10% + $0.10. The same card swiped in person runs 1.65% + $0.10. Interchange is non-negotiable.

Where the rest of your fee goes

LayerTypicalNegotiable?
Interchange1.65–2.50%No
Card network fee0.13–0.15%No
Processor markup0.20–1.50%Yes
Per-transaction fee$0.05–0.25Yes

The negotiable part is the markup — that is where flat-rate (Stripe, Square) and interchange-plus pricing diverge.

Interchange-plus vs. flat-rate

  • Flat-rate (Stripe 2.9% + $0.30): same regardless of card. Processor pockets the spread.
  • Interchange-plus (specialist 0.40% + $0.10): processor passes through interchange and adds a fixed markup. Effective ~2.4%.

On $50K monthly peptide volume, flat-rate costs $1,450/mo; interchange-plus costs ~$1,200. Annual savings: $3,000.

How peptide merchants legitimately lower interchange

  • Pass Level 2 data on B2B transactions (corporate cards qualify lower)
  • Enable 3D Secure 2.0 — shifts liability and unlocks lower CNP rates
  • Settle within 24 hours — late-settlement cards downgrade
  • Tokenise recurring billing with proper MIT flagging

Frequently asked questions

Why does my flat-rate processor not show interchange separately?

Because they keep the difference. The 2.9% Stripe charges bundles interchange (~2.0%), networks (~0.13%), and Stripe's markup (~0.77%).

Is interchange-plus always cheaper?

Above $20K monthly, yes. Below that, monthly fees can outweigh savings.

Does interchange change?

Visa and Mastercard publish updates in April and October. Most processors absorb the change quietly.

See interchange-plus credit card processing for full pricing on a peptide account.

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