Flat-Rate vs Interchange-Plus vs Tiered Pricing: Processing Models Compared
Compare flat-rate, interchange-plus, tiered, subscription and dual pricing, with arithmetic showing which model tends to fit which kind of business.
There is no universally cheapest pricing model. Flat-rate is usually best for new or low-volume businesses that want simplicity, interchange-plus is usually best for established merchants with steady volume who want transparency, subscription pricing can win at higher volume, and tiered pricing is the hardest to verify and is rarely the best choice. The right answer depends on your monthly sales, average ticket and card mix, and the only way to decide is to run your own numbers.
The five models in plain terms
Flat-rate. One percentage plus a fixed per-transaction fee for most cards, often with different rates for in-person, online and keyed-in sales. There is typically no long-term contract and little or no monthly fee. The provider absorbs the variation in interchange, so cheap cards subsidize expensive ones.
Interchange-plus (cost-plus). You pay the actual interchange and network assessments for each transaction, plus a stated markup, such as a percentage and a per-transaction fee. Your statement shows each transaction's category, which makes costs auditable.
Tiered. The processor sorts transactions into buckets, commonly called qualified, mid-qualified and non-qualified, each with its own rate. Which transaction goes into which bucket is decided by the processor, based on its own mapping to interchange categories.
Subscription or membership. A monthly fee covers access to a very low markup above interchange, often with a small per-transaction fee. It tends to suit merchants with enough volume that the monthly fee is small relative to the markup saved.
Cash discount or dual pricing and surcharging. These are not exactly pricing models from the processor, but programs in which the cost shifts to the customer. Rules apply, covered in surcharging and cash discount rules.
Worked example: same business, three models
Consider a retailer with $30,000 in monthly card sales and 600 transactions, so a $50 average ticket. All rates below are illustrative and not quotes.
Flat-rate at 2.7% plus $0.15. Percentage: $30,000 x 2.7% = $810. Per-transaction: 600 x $0.15 = $90. Monthly fee: $0. Total $900, an effective rate of 3.0%.
Interchange-plus at cost plus 0.30% plus $0.10. Assume interchange and assessments average 1.95% plus $0.10 per transaction. Cost portion: $30,000 x 1.95% = $585, plus 600 x $0.10 = $60, total $645. Markup: $30,000 x 0.30% = $90, plus 600 x $0.10 = $60, total $150. Monthly fees: $25. Total $820, an effective rate of about 2.73%.
Subscription at $99 per month with cost plus 0.08% plus $0.08. Cost portion $645 as above. Markup: $30,000 x 0.08% = $24, plus 600 x $0.08 = $48, total $72. Monthly fee $99. Total $816, nearly the same as interchange-plus at this volume.
At this size the subscription model is roughly tied with interchange-plus. At $10,000 monthly sales the subscription fee would dominate and flat-rate or interchange-plus might win. At $100,000 the subscription savings grow. You can reproduce this reasoning with the pricing model estimator and the fee calculator.
Side-by-side summary
| Model | Predictability | Transparency | Typical contract | Best fit |
|---|---|---|---|---|
| Flat-rate | High | Low | Often month to month | New, seasonal or low-volume sellers |
| Interchange-plus | Medium | High | Often fixed term | Established merchants |
| Tiered | Low | Low | Often fixed term | Few; rarely preferable |
| Subscription | High | High | Month to month or fixed | Higher-volume merchants |
| Surcharge or dual pricing | Depends on state and rules | Medium | Added to another model | Merchants who can comply and keep customers |
Why tiered pricing draws criticism
Under tiered pricing the processor publishes three rates but classifies transactions using its own rules. A rewards card or a keyed transaction is often tucked into a higher tier even if the actual interchange cost was moderate. Because the buckets do not map one-to-one to network categories, you cannot easily check whether you were charged fairly. If a quote is tiered, ask for the exact mapping of card types and acceptance methods to tiers, and compare the effective rate based on your last statements.
Choosing by situation
- Starting out, uncertain volume: flat-rate, as long as you avoid long contracts.
- Growing steadily, mostly in person: interchange-plus.
- High volume or many transactions: interchange-plus or subscription, with a clear view of monthly fees.
- Mostly small tickets: check per-transaction fees closely, since they weigh heavily.
- Mostly large tickets or business-to-business: percentage markup matters most, and enhanced data can lower interchange.
Questions to ask any provider
- Is this quote for the processor markup only, or the all-in effective rate?
- Which fees are monthly, annual or per item?
- Is any rate promotional, and when does it change?
- What are the term, renewal and early termination provisions?
- Can I get a sample statement showing how my transactions would be priced?
The pre-signing checklist covers the full list.
When to get help
If a contract includes a rolling reserve, a personal guarantee or a long term with termination penalties, have an attorney review it before you sign.
Frequently asked questions
Is interchange-plus always cheaper than flat-rate?
No. At low volume, the monthly fees and per-transaction markup of interchange-plus can exceed the simplicity premium of flat-rate. Calculate both.
Can I switch models mid-contract?
Only if your agreement allows it. Many fixed-term contracts impose termination fees.
Is subscription pricing worth it?
It can be, once volume is high enough that the saved markup exceeds the monthly fee. Compare using actual numbers.
Sources
- Federal Trade Commission — guidance on evaluating business service contracts
- Visa — interchange and acceptance rules
- Mastercard — merchant rules and interchange categories
- U.S. Small Business Administration — business planning and cost management resources