A customer hands you their debit card. Your terminal asks: debit or credit? Most cashiers hit credit out of habit. Most customers don't care either way. But that choice determines which network processes the transaction — and how much you pay.

The difference between PIN debit and signature debit can be 50–75% on the per-transaction cost. And almost nobody is paying attention to it.

How the same card takes two paths

Every debit card in the U.S. carries at least two network brands. One is a signature network — Visa or Mastercard — which routes the transaction the same way a credit card would. The other is a PIN network — Star, Pulse, NYCE, Shazam, Accel, or one of several others — which routes it through the debit-specific rails.

When the customer selects "debit" and enters a PIN, the transaction goes over the PIN network. When they select "credit" (or when the terminal defaults to credit), it goes over the signature network. Same card, same money, different pipes, different cost.

What each one costs

PIN debit interchange is structured differently from signature debit:

  • PIN debit — typically a flat fee per transaction, often in the range of $0.15–$0.35 regardless of the sale amount. Some networks add a small percentage (0.05%–0.15%).
  • Signature debit — priced like a credit card transaction, as a percentage plus a per-transaction fee. Regulated cards (Durbin) are capped at roughly 0.05% + $0.22, but non-regulated cards from smaller banks can be 0.8%–1.0% or higher.

For small-ticket transactions (under $20), the difference is minimal. But on larger tickets, PIN debit wins decisively.

A $200 sale on a regulated signature debit card costs about $0.32 in interchange. The same $200 on PIN debit might cost $0.25. That's a modest savings — but on a non-regulated debit card from a smaller bank, signature interchange could be $1.60–$2.00, while PIN debit stays in the $0.25–$0.35 range.

Why your terminal defaults to credit

Terminal manufacturers and processors often default to credit routing for debit cards. There are a few reasons:

  • Higher revenue for the processor. Signature debit generates more interchange, which means more margin for the processor on bundled and tiered pricing.
  • Visa and Mastercard incentives. The signature networks offer incentives to processors and merchants who route volume their way.
  • Simpler customer experience. No PIN pad interaction, no PIN entry. The transaction is faster.

None of these reasons benefit you, the merchant. They benefit everyone else in the chain.

How to route more transactions to PIN debit

The Durbin Amendment guarantees your right to choose which network processes a debit transaction. Your processor can't force you onto Visa or Mastercard exclusively. Here's how to take advantage:

  • Ask your processor to enable PIN-preferred routing. This tells your terminal to prompt for a PIN on debit cards instead of defaulting to credit. Some POS systems call this "debit-first" or "PIN-first" routing.
  • Train your staff. When a customer presents a debit card, ask "debit or credit?" and let them enter a PIN. Most customers are fine with it.
  • Check your terminal settings. Some terminals bury the PIN/credit default in a settings menu. Your processor can walk you through changing it, or you can ask during your next service call.
  • Review your statement for PIN vs. signature volume. If 90% of your debit transactions are running as signature, you're leaving money on the table.

When signature debit is fine

PIN debit isn't always the better deal:

  • Card-not-present transactions (online, phone orders) can't use PIN debit — there's no PIN pad. Signature routing is the only option.
  • Very small tickets (under $5) where the flat PIN network fee might actually be higher than the percentage-based signature cost.
  • Merchants on flat-rate pricing (Square, Stripe) who pay the same rate regardless of routing. In that case, routing doesn't affect your cost — only the processor's margin.

The bottom line

If you run a card-present business and more than a quarter of your volume is debit, PIN routing is one of the simplest ways to cut your processing costs. It requires no new hardware, no new processor, and no contract change — just a settings adjustment and a conversation with your staff. The savings show up on your next statement.