how much is one stamp
U.S. Forever stamps are only good for domestic mail. There is a Global Forever stamp that can be used world-wide. Otherwise, it costs $1.20 in postage to send up to 1 oz to the UK. Ooops! My initial response was based on old information. Several years ago the U.S. rules were change to allow non-denomination postage (e.g., Forever stamps) to be used on foreign mail.