1. There's no blanket travel cancellation policy. Policies and contracts of carriage vary from airlines to airline, hotel to hotel, and change all the time. It's best to check with your airline and hotel directly to find out what their current policies are before you go.
2. The closer you get to your departure date, the harder it is to change your policy.
3. Most hotels give full, or at least partial, refunds.
4. While it's more complicated with airlines, many carriers do make attempts to accommodate passengers. In the past, many airlines have allowed passengers to change their tickets within a specific time frame in the case of a terrorism attack with "Peace of Mind" policies that allow passengers to rebook tickets free of charge, or receive credit for a future trip. It's good business, and once one major airline allows changes, many follow suit.
5. Keep in mind that some airlines do not refund tickets purchased through a third-party discounter, or on the Internet through sites like Orbitz. Call the agency or packager you booked through first to see what's possible.
6. Always make your travel purchases with a credit card. If a hotel or airline closes, you'll be cover under the Fair Billing Act.
7. Consider buying insurance that covers war and acts of terrorism. If you already have insurance for your trip to London, read the fine print. Often you can cancel the trip and get a full refund.
8. For extra protection, always purchase travel insurance through a third party.
9. For traveling to London or any other international destination, expect to spend at least $200 to change your ticket, but contact the airline before your originally scheduled departure date. Changing tickets after the flight has left is much more complicated.
10. If you do decide to rebook your flight, be sure to find out the rules and regulations. Some airlines require that you make new reservations immediately, while others will allow you to rebook within a year.
Major airlines' contracts of carriage
Major airlines' refund policies