Visa and Mastercard are considering raising interchange fees on card transactions in the U.S. The two credit card issuers generate most of their revenue from these small processing fees.

Every time you make a purchase with a credit or debit card, merchants pay a small fee to the bank that issued this card, such as Chase or Barclays for example. Your bank then pays an even smaller fee to the company that operates the card network, such as Visa and Mastercard.

Mastercard and Visa will raise their fees in April. These fees are a small percentage of each transaction (about 10 cents plus 2% of the amount, but it varies by card) and the increase is expected to be barely noticeable, but they add up quite rapidly, especially for large merchants. And it’s usually the customer who ends up paying for them at the end through higher prices.

Read more at WSJ.