You may bring large sums of money with you in the form of cash, money order, or traveler's checks. There is no maximum limit, however, any amount exceeding $10,000 USD must be declared upon arrival on both the Form 6059B and FinCEN 105. All forms must be filled in completely and truthfully.
You can avoid United checked bag fees by paying more to travel in premium economy, business or first class. Passengers in these cabins receive two free checked bags on domestic flights. Those flying in business or first class have a 70-pound baggage allowance.
If you checked a bag, you'll have to collect it from baggage claim from the international flight. You'll need to clear customs and immigration. Next, you'll recheck your luggage for the domestic flight. Finally, you'll need to go through Transportation Security Administration screening.
Those who are traveling in business or first class and/or have elite status with United can check a bag up to 70 pounds for free — even on a basic economy ticket. If you're a heavy packer and your luggage weight usually exceeds 50 pounds, you may want to consider going for United elite status.
Ultimately, TSA uses the money to maintain and improve security operations. Travel Tip: To keep from leaving your money behind at the checkpoint, place it in a zip top plastic bag, pouch or favorite fanny-pack and store in your carry-on bag for X-ray screening.
United Express Carry-On Rules. United Express flights are operated by regional airline partners, who typically use smaller aircraft with less overhead space than United's regular aircraft. Often larger carry-on bags and roller bags will not fit in the overhead bins of Express aircraft.