Is the Delta Reserve Business Card a Visa or Mastercard?
Delta SkyMiles® Reserve Business American Express Card is not a Visa or a Mastercard – it is on the American Express network. This means the Delta Reserve Business Card has a bit less worldwide acceptance than a Visa or a Mastercard but should still be usable at most merchants within the U.S.
In general, it doesn't matter much what network your credit card is on unless you're focusing specifically on international travel. In that case, you're best served by getting a Visa or Mastercard credit card with no foreign transaction fees. But for all other purposes, all four major credit card networks have comparable benefits and card offers. It's best to compare individual cards on a case-by-case basis rather than focusing on a specific network.