You open your processing statement, scroll past three pages of fees, and still cannot say what a card sale actually costs you. Most store owners treat that number as fixed. It is not.
If you use Stax through ShelfPerks, you are on flat rate pricing, so you pay the same rate on every card.
Key takeaways
- Your effective rate, total processing fees divided by total card sales, is the only fair way to compare processors.
- Flat rate through Stax keeps pricing simple and predictable, which suits newer and lower-volume stores that value an easy statement.
- In our hypothetical examples, a sample interchange-plus quote cost less than a sample flat rate at every volume, and the gap grew as sales grew, so run your own numbers once a year.
- ShelfPerks lets you register for Stax while setting up your store system, and you can switch to another supported processor later without changing your store system.
How does payment processing pricing work?
Every card payment has the same basic ingredients. The card's issuing bank and the card network charge interchange and network fees, which vary by card type. Your processor then adds its own markup. The pricing model decides how that markup shows up on your statement.
Flat-rate pricing
Flat-rate pricing charges one percentage plus a fixed amount on every transaction, whatever card the customer uses. It is easy to understand and easy to budget for. The trade-off is that you pay the same rate on a low-cost debit card as on an expensive rewards credit card, so the processor's margin is built into the average.
Interchange-plus pricing
Interchange-plus pricing passes the actual interchange cost through and adds a stated markup, such as a percentage plus a few cents per transaction. It is more transparent, and it often costs less as volume grows. The downside is a longer statement, and your effective rate moves with your customers' card mix.
Subscription and tiered pricing
Across the industry you will also see subscription pricing, which swaps the percentage markup for a monthly fee, and tiered pricing, which sorts cards into buckets such as "qualified" and "non-qualified." Neither is offered through ShelfPerks at this time. They may still show up in quotes you collect elsewhere, so it helps to recognize them.
| Pricing model | How the processor earns | Through ShelfPerks | Best suited to |
|---|---|---|---|
| Flat rate | Percentage plus a fixed fee on every sale | Stripe, Stax and other processors | New or lower-volume stores that value simplicity |
When does flat rate through Stax make sense?
Flat rate earns its place when simplicity is worth more to you than the last fraction of a percent. Flat rate through Stax tends to fit:
- Newer stores that do not yet know their card mix or monthly volume.
- Stores with low or uneven card volume, where a predictable rate is easier to budget than a statement that moves with every card.
- Owners who do not want to check interchange line items every month.
- Stores where many customers pay with premium rewards credit cards, since a flat rate does not rise with the card's interchange cost.
The trade-off works the other way for a debit-heavy store. A busy convenience store where most customers tap a debit card pays the same averaged rate on every one of those low-cost transactions.
How much does flat rate cost as you grow? Three worked examples
The examples below are hypothetical. They compare a sample flat rate of 2.6% + 10 cents with a sample interchange-plus quote of interchange + 0.30% + 10 cents. Both assume an average interchange cost of 1.5%, which is an illustration, not a benchmark. Your real interchange depends on your card mix.
Example A: small grocery, $15,000 a month, 333 card sales
| Pricing model | Monthly cost | Annual cost |
|---|---|---|
| Sample flat rate (2.6% + $0.10) | $423.30 | $5,080 |
| Sample interchange-plus (interchange + 0.30% + $0.10) | $303.30 | $3,640 |
In this example, the sample interchange-plus quote costs $120 a month less, about $1,440 a year.
Example B: convenience store, $30,000 a month, 600 card sales
| Pricing model | Monthly cost | Annual cost |
|---|---|---|
| Sample flat rate (2.6% + $0.10) | $840.00 | $10,080 |
| Sample interchange-plus (interchange + 0.30% + $0.10) | $600.00 | $7,200 |
Here the gap is $240 a month, or $2,880 a year.
Example C: two-location health food store, $75,000 a month, 1,786 card sales
| Pricing model | Monthly cost | Annual cost |
|---|---|---|
| Sample flat rate (2.6% + $0.10) | $2,128.60 | $25,543 |
| Sample interchange-plus (interchange + 0.30% + $0.10) | $1,528.60 | $18,343 |
At this volume the gap is $600 a month, about $7,200 a year.
What the examples show
Both samples charge the same 10 cents per sale, so the whole gap comes from the percentage: 2.6% against 1.8% (1.5% interchange plus 0.30%). That 0.8-point difference applies to every dollar, which is why the cost of flat rate's simplicity grows in step with your sales. If your customers use more rewards cards, interchange rises and the gap shrinks. If more of them pay by debit, the gap widens. Compare real quotes, not sample rates.
Why does your card mix change what you pay?
Interchange is not one number. Debit cards generally cost less to accept than credit cards, and premium rewards cards generally cost more than basic ones. Card-not-present sales, such as online orders, usually cost more than tapped or dipped cards.
That is why two stores with the same sales can pay very different amounts. A store where most customers pay by debit gets the most benefit from interchange-plus, which passes interchange through at cost. A flat rate charges both stores the same, so the debit-heavy store pays for everyone else's rewards cards.
How do you lower your payment processing fees on flat rate? A Five-step plan
- Calculate your effective rate. Add up every fee on your last three statements, including monthly, PCI and statement fees, and divide by your total card sales.
- Confirm your rate in writing. Ask Stax or ShelfPerks for the flat rate that applies to your ShelfPerks store, and ask whether online or keyed payments are priced differently from in-person ones.
- Cut the fees around the rate. Look for monthly, PCI, statement and minimum fees on your statement, ask which ones can be removed, and check contracts for early termination fees and hardware leases.
- Watch your average sale. Fixed per-transaction cents hit small sales hardest, so stores with many small sales should compare the cents as well as the percentage.
- Count your provider accounts. ShelfPerks charges a $20 integration fee per provider account, per location, per month, so a processor account you no longer use still costs you every month until you remove it.
How do ShelfPerks and Stax work together?
ShelfPerks' Stax partner page says you can register for Stax payment services while setting up your ShelfPerks Store Operating System and track your Stax application status in the ShelfPerks Merchant Portal. The page also notes that Stax supports mobile payments and e-commerce. Through ShelfPerks, Stax is priced at a flat rate.
Card sales flow into the same system that runs your inventory, real-time analytics and staff roles, so your sales and stock counts update from the same transactions.
ShelfPerks charges a payment provider integration fee of $20 per provider account, per location, per month, separate from Stax's fees. ShelfPerks plans start with a Free plan, and Standard is $29.95 a month billed annually. See the pricing page for every plan, and our ShelfPerks payment processing guide for how processor connections work.
Should you stay on flat rate or switch to interchange-plus?
Stay on flat rate through Stax if your volume is modest or uneven, your card mix leans toward rewards cards, or you value a simple statement over a small saving. Look at interchange-plus through when your volume is steady and growing and many of your customers pay by debit. The only way to know is to run your own statement through the comparison above.
When you are ready, explore the processors on the ShelfPerks payments page and start a 14-day free trial of ShelfPerks Premium features, with no credit card required.
Frequently asked questions
What does Stax charge through ShelfPerks?
Through ShelfPerks, Stax is flat rate only for now, so you pay the same rate on every card. Ask Stax or ShelfPerks for the current rate for your store, and add ShelfPerks' $20 per provider account, per location, per month integration fee.
Is interchange-plus cheaper than flat-rate pricing?
Often, as volume grows. In our hypothetical examples, a sample interchange-plus quote cost less than a sample 2.6% + 10 cent flat rate at $15,000, $30,000 and $75,000 a month. A store with many rewards cards will see a smaller gap, so compare real quotes.
What is an effective processing rate?
Your effective rate is your total processing fees divided by your total card sales for the same period. It includes every monthly and per-transaction fee, so it shows what card payments really cost you.
Can I use Stax with ShelfPerks?
Yes. Stax is one of the payment processors ShelfPerks supports. You can register for Stax while setting up ShelfPerks, and ShelfPerks charges a $20 per provider account, per location, per month integration fee.
