Merchant Account Types Explained: Flat-Rate vs. Interchange-Plus vs. Tiered Pricing for High-Risk Businesses

The fees for flat-rate pricing include the cost of credit cards plus the markup charged by payment processing companies. These companies may offer different rates for different types of transactions. For instance, Square offers different rates for in-person transactions versus online transactions. Square’s Square Free program, for instance, charges merchants 2.6% plus 15 cents for tap, dip, or swipe payments and 3.3% plus 30 cents for online transactions. These rates can change and some special businesses may not be eligible for these rates.

The benefit of a flat-rate pricing program is that merchants do not have to worry about which interchange category is associated with the customer’s card. The payment processing company absorbs that cost within the flat rate for each card.

The disadvantage to flat-rate programs is that the merchant will always pay the same rate for each transaction, even if the underlying transaction costs less. Therefore, if a business uses a lot of debit cards or has high sales, they may pay more with a flat-rate program than they would with a different type of transaction fees program.

Flat-rate payment processing may be useful for merchants who have:

• low volumes of payments to process
• no need for sophisticated bookkeeping software
• seasonal sales that prevent consistent transaction logging
• very limited time to review transaction and bookkeeping software statements
• only use one provider for transaction and bookkeeping software

High-risk merchants usually have fewer options for flat-rate payment processors, as most find it difficult to offer flat rates to merchants in certain industries. The flat rate is unlikely to be of much use to merchants if the payment processor does not offer the types of products and services that are commonly processed by high-risk merchants.

Interchange-plus pricing separates the cost of the transaction from the markup that the processor adds to that transaction.  The cost of the transaction often shows up on the statement as interchange and assessments, followed by the percentage and fee the processor adds to the transaction.

For example, the statement may read:

Interchange and assessments + 0.45% + $0.20

The cost of the transaction varies based on the card that is used, the transaction method, the merchant category and other factors that impact the merchant’s qualification for the transaction. The percentage and fee that the processor adds to the transaction are easier to read and compare.

While Helcim states that it uses an interchange-plus model with different rates for merchants based on transaction volume and type (in-person versus keyed online transactions), Helcim is primarily an example of interchange-plus pricing, not an example of the model’s support of high-risk industries.

Interchange-plus pricing may work well for merchants who have:

• volume that is consistent from month to month
• access to monthly statements
• a good mix of debit and card types
• processing history to establish rates
• separate costs for wholesale and retail sales
• high-risk needs for custom rates

The main tradeoff with interchange-plus rates is that the cost may be variable within a given month. Because rewards, international, corporate and card-not-present transactions typically have different interchange fees, merchants will encounter some variation in the costs that arise from these different sale types.

Even with the cost transparency of interchange-plus pricing, the rates can be high if the processor has high fees for its products and services. While the transparency of interchange-plus makes it easier for merchants to understand the costs of each transaction type, it does not promise that those costs will necessarily be low.

Tiered pricing considers various factors to determine which category a transaction falls into. Transaction categories are defined by the payment processor as qualified, mid-qualified, and non-qualified.

Transactions that do not meet the criteria set by the payment processor will be downgraded to a higher tier that reflects an increased cost for the organization completing the transactions.

The issue with tiered pricing is that each payment processor will define the different transaction categories differently. What may be considered a mid-qualified transaction by one payment processing company may be considered a non-qualified transaction by another. The merchant will only see the rate applied to the transaction based on the tiered pricing model, not the interchange rate and the payment processor’s margin.

Before accepting a proposal that includes tiered pricing, ask the following questions:

• Which transactions will be priced at the lowest rate?
• What can cause a transaction to be downgraded from the qualified rate?
• What can cause a transaction to be downgraded from the qualified rate without being qualified for the rate?
• Are business and rewards cards placed into higher tiers?
• Into which tier are ecommerce and manually entered transactions placed?
• Does the statement include the volume of transactions in each tier?
• Are there surcharges for downgrades to lower tiers that are included in the proposed rate?
• Can the payment provider change the definition of each tier?

Tiered pricing is not automatically unsuitable. It becomes problematic when the provider promotes the qualified rate without explaining how many transactions are likely to receive it.

While each of the three main models for high-risk payments may be utilized by the provider, there can also be a variety of costs and restrictions placed upon these models that are not reflected in the advertisements for these companies with low risk levels.

These can include:

• Markup on risk-based processors
• Reserves that are rolled in or fixed
• Delayed funding
• Minimum monthly fees
• Higher chargeback fees
• Requirements for payment gateways and fraud-detecting tools
• Limits on the maximum ticket sizes for accepted payments
• Caps on the number of payments that can be processed each month
• Costs associated with international payments
• Fees associated with account review and compliance

Note that rolling reserves are not permanent fees for businesses using these processors for their card payments. These percentages of sales are held by the processor for a defined period of time before being released to the business according to the established agreement between the company and the payment processor.

It is also possible that a company with a slightly higher markup on its accepted payment transactions may be an easier model to operate than a business with a lower rate but high reserve fees that hold 10% of all sales within the processing account. Thus, while a business may be offered the cheapest rate for processing payments, it does not always mean that the provider will have the lowest cost for the business to operate at its desired levels.

The effective rate represents the percentage of a merchant’s processing volume that was consumed by processing fees during a particular period.

Effective rate = total processing costs ÷ total processed sales × 100

Suppose a merchant collected $100,000 in sales during a period and paid $3,600 in processing fees. In that case, the merchant’s effective rate would be 3.6%.

Include the following costs when calculating your effective rate:

• discount and transaction fees
• processor markup
• gateway fees
• monthly charges
• PCI-related fees
• card-network costs
• non-qualified surcharges
• batch and statement fees

Examine your reserves separately. Reserved amounts will eventually be released back into your account. Additionally, investigate your chargebacks separately from your total sales. Losses resulting from chargebacks, returned merchandise, and fraud should be evaluated separately from your effective rate.

Assess your effective rate over several months rather than one monthly sales statement. Sales that contain a high percentage of seasonal cards, high-ticket purchases, chargebacks, and annual fees can skew individual monthly statements.

Visa announced in June 2026 that a preliminary approved merchant settlement would reduce the combined average effective U.S. credit interchange rate by 10 basis points for five years. Ten basis points is equivalent to 0.10 percentage points.

That 0.10 percentage point change would result in every company that processes $100,000 saving $100. Although this is yet to be finalized through the court system, merchants that process millions of dollars every year pay close attention to these small changes to the interchange rates.

The same is true of processor markup. Reducing a markup by 0.20 percentage points may be more beneficial to a high-volume merchant than eliminating a small flat fee.

A merchant with low sales volumes, however, may not see it the same way. A few basis points off the rate may not compensate for a high monthly cost.

The flat rate model may offer economical solutions for small businesses. However, the interchange plus model provides more transparency and potentially significant savings for merchants who have been in business for longer and feature a better card mix. The tiered rate model is best for merchants who understand the qualification requirements and have a high volume of transactions falling within the lowest spend tier.

For high-risk businesses, it is also important to compare the qualification requirements for each company. A company that offers low rates may not accept your type of business or transaction volume.

The best credit card processing company for your business will depend on a few factors, including:

• Monthly processing volume
• Number of transactions
• Average ticket size
• Card-present and card-not-present sales
• Debit, rewards, and commercial card sales
• International sales
• Refund and chargeback rates
• Gateway and software requirements
• Reserve requirements
• Funding speed
• Contract length
• Account stability

Payment Nerds can compare credit card processing companies based on the factors above to determine what will yield the best rate of return for your business. The rate you receive will be determined by your industry, your business account history, your payment channels, and the outcome of your underwriting process.

The Visa Acquirer Monitoring Program (VAMP) does not establish rates for merchants. VAMP creates a framework for Visa and the acquiring banks to monitor fraud, disputes, and enumeration for card-not-present transactions.

While there is no direct link between VAMP and pricing for merchants, high levels of fraud and disputes will have an indirect effect on the pricing for the merchants involved. The processor may require a reserve or implement risk controls on merchants with high potential liability for chargebacks and fraud.

Merchants classified as high-risk should monitor their disputes according to the products sold, sales channel and traffic source. By reducing fraud and chargebacks for high-risk merchants, those merchants may be able to request a review of their prices after several months of stable transactions.

A merchant will be more successful in negotiating pricing with the processor if they can provide proof of:

• monthly transaction volume
• declining dispute rates
• strong controls for refunds
• fulfillment of shipped products
• accurate product billing descriptors
• low levels of fraud
• transactions within established limits

Ask each provider for a complete written schedule before you begin to compare proposal after proposal.

Review each proposal for the following items:

• Pricing model and processor markup
• Per-transaction charges
• Gateway and virtual-terminal fees
• Monthly and annual charges
• Batch and statement fees
• Chargeback and retrieval fees
• Cross-border and currency fees
• Reserve percentage and release terms
• Funding schedule
• Monthly minimums
• Processing caps and maximum tickets
• Contract and termination terms
• Hardware purchases or leases
• PCI-related charges
• Conditions for future pricing reviews

Ensure the statement analysis uses the merchant’s actual card mix. Generic estimates of potential savings may be inaccurate if the provider assumes that every transaction incurs the rate quoted in the proposal.

The most common mistake is comparing one advertised rate to another company’s advertised rate.

Other common mistakes include:

• Assuming interchange is the processor’s complete rate
• Only considering the qualified rate
• Ignoring gateway and account fees
• Not including reserves in cash flow projections
• Choosing a flat rate without determining if volume will be high enough to support such a rate
• Choosing an interchange plus rate without considering markup
• Not being clear on the rules for downgrading rates
• Comparing rates using different transaction volumes
• Overlooking keyed and ecommerce rates
• Choosing to lease the terminal for a long term
• Not asking when the rate can be reviewed
• Choosing a provider that does not support the business model

The rate must be evaluated with the underwriting and the stability of the account. A low rate may sound great, but if the account will hold funds frequently or if it cannot support the growth of the business, it is not an ideal choice for that company’s future.