Accepting Diners Club as a merchant

This is the pattern worth naming. Diners Club volume is usually too small to attract attention on a monthly statement, so the rate applied to it is whatever the acquirer set, often well above your card average, and it stays there indefinitely. The amounts are small in absolute terms and the percentage is not. Whether that is worth acting on depends on your volume, but it is worth knowing rather than assuming.

Corporate travel and expense spending has a structural feature consumer volume does not: the person holding the card is not the person paying for the purchase. The employee books, the company settles, and a finance team reviews the line weeks later against a receipt and an expense policy.

That distance shows up in your dispute rate. A consumer disputes a purchase they remember making. A company disputes a line nobody in the room can identify, which is a different failure and a far more fixable one. What fixes it is the descriptor that appears on the statement, the invoice or receipt the cardholder can attach to an expense claim, and whether your order confirmation carries a reference a finance team can match. Those three things cost nothing and they are the difference between a query and a chargeback.

If corporate volume is a real part of your revenue, look at the dispute rate on it separately from your consumer rate. If it is higher, the cause is far more likely to be your descriptor than your product.