In the United States, there are no laws which forbid people from carrying money in the form of cash on an airplane. It doesn’t matter how much cash you want to fly with on a plane because there are no legal limits set for it.
You can fly with as much cash as you want.
Of course, how many people are actually going to bring briefcases filled with hundred dollar bills onto a plane? You may see this done in the movies, but it is rarely done in real life. Anyone who brings cash on a plane should only bring enough to keep in their wallet or purse. If you need to put cash in your luggage, make sure you use a sturdy lock on it to prevent theft.
When carrying cash on a plane, domestic flights are straightforward. There are no extensive customs checkpoints when flying domestically, only TSA agents and security screening. If TSA notices you carrying lots of cash, they may wonder what you’re doing with it. This could lead to questioning and a mini-investigation which could take minutes or even hours of your time. So, be prepared for that if you go through airport security with lots of money.
International flights also have no limits for carrying cash. However, you are required by law to declare your cash on a customs form if the total you’re flying with is over $10,000. This includes traveler’s checks, blank money orders, foreign currencies, and other monetary instruments equivalent to 10,000 or more in U.S. Dollars.
The form you will need to fill out when flying internationally with more than $10k is called FinCEN Form 105 “Report of International Transportation of Currency or Monetary Instruments”.
Once you submit that form with customs, you can expect airport security and possibly even law enforcement officers to question you about the money. Do not be intimidated by them because they are just doing their job. They want to make sure you’re not a money launderer or drug dealer. If you can provide truthful answers for why you’re carrying all this cash on you, then they will let you proceed on your trip.
Now that we’ve gotten the legal aspects of carrying cash on a plane out of the way, let’s talk about how much is safe to carry.
It is never a good idea to have no cash in your possession when you travel because you might end up someplace where none of the merchants accept credit cards or debit cards. If you have no cash on you, then there’s the possibility of running into a problem.
As a word to the wise, don’t carry more than $1,000 on you whenever you travel by plane. Keep the cash in $20 bills or $100 bills in your wallet or purse. Keep it next to you on the plane always. Never put it in the overhead storage compartment or in your suitcases. If you can remember that, then you’ll be in good shape.