Most business owners sign up for a payment processor, start accepting cards, and don’t understand the details behind card processing, whether that’s a surprise fee on a statement, a chargeback they don't know how to fight, or a rate increase buried in the fine print. The less you understand, the easier it is to overcharge you. You as a business owner don't need to become a payments expert, but knowing the core terminology puts you in a better position to compare processors, read your statements, and push back when something doesn't add up. Here's what you need to know.

Interchange: the foundational fee in card payments. Interchange is set by card networks like Visa and Mastercard, not by your processing partner. Interchange is the actual amount that travels from your customers bank to the card network any time a transaction occurs. Rates will always vary dependent on the card type: basic debit cards cost less than premium travel rewards cards. Because of this, the processor will always pass the cost along to you, and the processors have very little control over it.

Discount Rate: the percentage your processor deducts per transaction. It wraps together interchange, card network fees, and the processor's own margin. When a processor advertises a rate like "2.9% + $0.30," that's the Discount Rate. Flat-rate pricing is predictable and consistent month-over-month and interchange-plus pricing is usually the more transparent option and cheaper at higher volumes.

Authorization: the first step in any card transaction. Your processor sends a request to the cardholder's bank asking whether the card is valid and whether the funds are available. An approval reserves the amount, but it doesn't move money yet.

Settlement: when the reserved funds transfer into your merchant account, typically one to two business days after the transaction, depending on if your processor gives you access to next day funding. Authorization and settlement are two separate events, which is a critical distinction for accounting and cashflow purposes.

Chargeback: a forced transaction reversal initiated by a cardholder through their their bank, not directly with you. Whether the dispute is legitimate or fraudulent, you lose the sale amount and pay a chargeback fee (typically $15–$25 per incident). Processors monitor chargeback ratios closely to ensure that their merchants don’t exceed chargeback thresholds (typically around 1% of transactions). You as the merchant can continue to fight this process out in Arbitration if you’re able to provide sufficient evidence of the sale and process.

PCI DSS stands for Payment Card Industry Data Security Standard. It's the set of security requirements governing any business that stores, processes, or transmits cardholder data. Compliance is mandatory, not optional.

Tokenization is a security method that replaces sensitive card data with a randomized string of characters (a token). It reduces your exposure if your systems are ever breached, since tokens are useless outside the specific payment environment they were created for.

Knowing these terms won't automatically lower your processing costs. But it changes the dynamic with your processor—and in payments, that matters.

‍