# Flat rate versus interchange-plus

Title: Flat rate versus interchange-plus

Description: Where a blended rate stops being the cheap option, without pretending interchange is one number. Read November 9, 2026. Source pages linked.

A flat rate, Stripe's 2.9% + $0.30, hides the card network's interchange inside a blend. You pay the same on a regulated debit card and on a corporate rewards card. The processor wins on the cheap cards and hopes the expensive ones are rare enough.

## What does interchange-plus show that a flat rate hides?

Interchange-plus shows the network's cost and adds a markup. Helcim's base online markup is **0.50% + $0.25**, stepping down as monthly volume rises. Your total moves every time the mix moves.

## What does the labeled interchange model cost?

There is no universal crossover volume, because there is no universal interchange. A planning assumption used on this site is **1.80% + $0.10** of blended card-not-present interchange. Stacked on Helcim's base markup, that is **2.30% + $0.35**. At a $50 ticket and $10,000 a month, the model says **$300** versus Stripe's **$350**. At $250,000 a month, Helcim's published tier is lower and the gap widens, in the model.

Change the assumption to a rewards-heavy book and the model can flip. That is the point of showing the assumption instead of crowning a winner. The calculator lets you edit it.

## Which prices are not in this contest?

Two flat-rate traps sit beside this. The fixed fee dominates small tickets, so "2.9%" is not your effective rate. And a merchant of record at 5% is not in this contest. You are paying it for tax and for someone else to be the seller, not for a clever interchange strategy.

## When should you switch?

Switch when the statement you were shown, on your mix, beats Stripe by enough to pay for the migration. A blog's crossover chart is not that statement.

## Questions

### What does interchange-plus show that a flat rate hides?

Interchange-plus shows the network's cost and adds a markup. Helcim's base online markup is 0.50% + $0.25, stepping down as monthly volume rises. Your total moves every time the mix moves.

### What does the labeled interchange model cost?

There is no universal crossover volume, because there is no universal interchange. A planning assumption used on this site is 1.80% + $0.10 of blended card-not-present interchange. Stacked on Helcim's base markup, that is 2.30% + $0.35. At a $50 ticket and $10,000 a month, the model says $300 versus Stripe's $350. At $250,000 a month, Helcim's published tier is lower and the gap widens, in the model.

### Which prices are not in this contest?

Two flat-rate traps sit beside this. The fixed fee dominates small tickets, so "2.9%" is not your effective rate. And a merchant of record at 5% is not in this contest. You are paying it for tax and for someone else to be the seller, not for a clever interchange strategy.

### When should you switch?

Switch when the statement you were shown, on your mix, beats Stripe by enough to pay for the migration. A blog's crossover chart is not that statement.

### Where were the figures on this page read?

The sources list names the pages. This edition was read on November 9, 2026. Stripe's US domestic card rate in that reading is 2.9% + $0.30, and a dispute received is $15.

## Sources

Last verified November 9, 2026.

- Stripe pricing: https://stripe.com/pricing?ref=https%3A%2F%2Fwww.stripealternatives.com

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