How much cash per person is allowed on a flight?

There is generally no limit on the amount of cash you can carry on a flight within the U.S. However, if you are traveling internationally and carrying more than $10,000 in cash or its equivalent, you must declare it to customs. Different countries may have their own regulations regarding the amount of cash that can be transported, so it's important to check the specific rules for your destination. Always ensure you keep cash secure and easily accessible during your travels.