Restaurant owners have a consistent complaint about credit card processing: overcharges on credit card processing that nobody catches until months of overpayment have stacked up. One operator told us their POS company double charged me for 3 months before the bookkeeper noticed a duplicate fee line item buried on page three of the monthly statement. Another said it plainly: there are hidden fees you have to watch or they’ll quietly eat your margins.

Processing fees are one of a restaurant’s largest non-labor expenses. On $50,000 in monthly card sales, even a 0.5% overcharge costs $250/month — $3,000/year. This guide gives you a step-by-step audit process to verify your processing fees, spot hidden charges, and dispute overcharges with documentation your processor can’t ignore.

If your processing fee issues overlap with delivery platform charges, our guide on hidden delivery fees most restaurants miss covers that adjacent problem.

What normal processing fees look like

Before you can identify overcharges, you need to know what normal looks like. Restaurant credit card processing fees fall into three pricing models.

Interchange-plus pricing. You pay the actual interchange rate (set by Visa, Mastercard, etc.) plus a fixed markup from your processor. Interchange rates vary by card type — a basic Visa debit card costs less than an American Express rewards card. Typical processor markups run 0.2–0.5% plus $0.05–$0.10 per transaction. This is the most transparent model and the easiest to audit because you can see exactly what the processor charges versus what the card network charges.

Flat-rate pricing. You pay a single rate on every transaction regardless of card type. Square charges 2.6% + $0.10 per tap/dip. Toast charges 2.49% + $0.15 on most plans. Flat-rate is simple but usually more expensive than interchange-plus for restaurants processing more than $15,000/month, because you’re paying the same rate on cheap debit cards as on expensive rewards cards.

Tiered pricing. Your processor groups transactions into “qualified,” “mid-qualified,” and “non-qualified” tiers, each with a different rate. This is the hardest model to audit because the processor decides which tier each transaction falls into, and there’s often no clear rule for the classification. Most industry experts consider tiered pricing the worst deal for merchants.

Across all models, a restaurant’s effective rate (total fees divided by total card volume) should fall between 2.5% and 3.5%. If yours is consistently above 3.5%, something is wrong.

Red flags that you’re being overcharged

You don’t need to understand every line item to spot a problem. These five red flags indicate your processing costs are higher than they should be.

Effective rate above 3.5%. Calculate your effective rate: total processing fees ÷ total card volume. If it’s above 3.5% consistently, you’re either on a bad plan, paying hidden fees, or being charged rates that don’t match your contract.

Fee categories you don’t recognize. Processing statements often include line items like “regulatory fee,” “technology fee,” “network access fee,” or “account maintenance fee.” Some of these are legitimate pass-through costs; others are pure processor markup. If you can’t find a fee in your original contract, it may have been added after signing.

Rates that changed without notice. Processors can raise rates, but they’re required to notify you. Many bury the notification in fine print at the bottom of a monthly statement. If your effective rate jumped from 2.8% to 3.4% between months, check whether you received a rate change notice.

Monthly minimum fees. Some contracts include a minimum processing fee — if your card volume doesn’t generate enough fees, you pay the difference. During slow months, this can significantly inflate your effective rate.

Duplicate charges. This is rarer but not unheard of. Batch fees, PCI compliance fees, or statement fees occasionally appear twice on the same statement. Unless you read every line, you’d never know.

How to audit your processing fees step by step

Step 1 — Pull 3 months of processing statements

Get your monthly processing statements for the last 3 months. These come from your payment processor (not your POS company, unless they’re the same entity). You need the full statements with line-item detail, not just the summary page.

Step 2 — Calculate your effective rate for each month

For each month: divide total fees by total card volume. Track whether this rate is consistent month to month. A rate that fluctuates by more than 0.3% between months suggests variable fees or billing irregularities.

Step 3 — Compare to your contract

Pull out your original processing agreement. Compare the contracted rate to your effective rate. If you’re on interchange-plus, verify the markup percentage and per-transaction fee match what you signed. If you’re on flat-rate, the math is simpler — multiply your contracted rate by your volume and compare to actual fees charged.

Step 4 — Identify every fee category

List every unique fee line item across your 3 months of statements. Common legitimate fees include interchange fees, processor markup, authorization fees, and batch settlement fees. Common questionable fees include PCI non-compliance fees, annual fees, statement fees, regulatory recovery fees, and technology surcharges. For each fee, determine whether it’s in your contract.

Step 5 — Document discrepancies

For each overcharge or unrecognized fee, note the statement date, fee description, amount charged, and what your contract says. Calculate the total overpayment across 3 months. This becomes your dispute evidence.

Step 6 — File disputes with documentation

Contact your processor’s merchant services team with your findings. Lead with specific dollar amounts and contract references, not general complaints. Most processors will credit overcharges back to your account when presented with clear documentation.

Processing fees are just one place restaurants lose money. See the full picture across your POS, delivery platforms, and bank.

Run a Free Scan

Hidden fees restaurant POS companies don’t explain

Beyond the obvious processing rate, several fee categories quietly inflate your costs. These are the ones operators miss most often.

PCI compliance fees ($10–$30/month). Charged for maintaining PCI DSS compliance. Some processors charge this monthly whether you’ve completed your PCI self-assessment or not. Others charge a “PCI non-compliance fee” ($25–$100/month) if you haven’t completed their compliance questionnaire — a fee that disappears the moment you fill out a 15-minute online form.

Statement fees ($5–$15/month). A monthly charge for generating your processing statement. In 2026, this is pure profit for the processor — statement generation costs pennies. Some contracts waive this fee for electronic-only statements.

Batch fees ($0.10–$0.30 per batch). Charged every time you settle a batch of transactions (typically once daily). At $0.25 per batch, that’s $7.50/month — not enormous, but it adds up alongside other small charges.

Monthly minimums ($25–$50/month). If your processing fees don’t reach a minimum threshold, you pay the difference. This primarily affects low-volume months and new restaurants ramping up.

Early termination fees ($200–$500). Not a monthly fee, but worth knowing: many processing contracts include an early termination fee if you switch providers before the contract ends. This locks restaurants into bad rates even after discovering overcharges.

For delivery-specific hidden charges, see our breakdown of how delivery platforms overcharge restaurants.

How to dispute POS processing overcharges

Disputing processing fees requires documentation, not just complaints. Processors deal with unhappy merchants daily — what gets results is specific evidence.

Lead with numbers. “My effective rate is 3.7% but my contract says 2.9% plus interchange” is a dispute. “I think my fees are too high” is a complaint. Disputes get resolved; complaints get ignored.

Reference your contract. If fees appear that aren’t in your original agreement, say so explicitly. “The $19.95 monthly technology fee does not appear in my signed merchant agreement dated [date]” is hard for a processor to argue with.

Request retroactive credits. If you’ve been overcharged for months, ask for credits covering the full overpayment period. Most processors will credit 3–6 months of overcharges to retain the account.

Get the resolution in writing. Any rate adjustment or fee removal should be confirmed via email or an amended agreement. Verbal promises from merchant services reps don’t always make it into the billing system.

Processing fee discrepancies are just one piece of the puzzle. If your restaurant also runs delivery through DoorDash or Uber Eats, our POS deposit mismatch guide explains why your total deposits are off, not just the processing fees.

How DeliverGuard helps track processing fee accuracy

Processing fee audits are one piece of the revenue integrity puzzle. Most restaurants lose money across multiple channels simultaneously — processing fees from their POS, commission overcharges from delivery platforms, and deposit discrepancies at the bank.

DeliverGuard tracks all three. Upload your POS data, delivery platform statements, and bank deposits, and the system identifies every discrepancy — including effective processing rates that don’t match expectations. If your deposits are short because of processing fee errors, you’ll see exactly where the gap is. If you also want to check whether your POS deposits match your bank account, DeliverGuard handles that comparison automatically.

Find out if your POS is overcharging you. Free scan, no credit card required.

Run a Free Scan

Related POS reconciliation guides

Frequently Asked Questions

Restaurant credit card processing rates typically range from 2.5% to 3.5% of the transaction amount. This includes interchange fees (set by card networks), processor markup, and any additional fees. If your effective rate consistently exceeds 3.5%, you are likely paying hidden fees or surcharges that should be investigated.

Divide your total processing fees for the month by your total credit card sales volume. For example, if you processed $50,000 in card sales and paid $1,750 in total processing fees, your effective rate is 3.5%. Compare this to your contracted rate. If the effective rate is more than 0.3% above your contracted rate, hidden fees are inflating your costs.

PCI compliance fees are monthly charges ($10–$30) that processors add for maintaining Payment Card Industry data security standards. Some processors include PCI compliance in their base rate; others charge it separately. If you are paying a PCI compliance fee, verify that your processor is actually providing PCI compliance services and not just adding a line item.

Yes. Document the discrepancy between your contracted rate and your effective rate with at least three months of statements. Contact your processor’s merchant services department with specific line items and dollar amounts. Most overcharges are resolved with credits applied to future statements. If the processor refuses to correct verified overcharges, you may have grounds to exit your contract.

Quarterly at minimum. Processing fees can change without clear notification, especially after contract renewals or rate reviews. A quarterly audit takes about 30 minutes and can catch rate increases, new fee categories, and billing errors before they compound over months.