You can use UK stamps if you are shipping from within the UK. They are not valid for shipping anywhere else. When using stamps to pay for postage, the various stamp values may be added up to get the needed sum. A first-class stamp is currently worth 67p, while a second-class stamp is worth 58p. Envelopes are also used in combination with stamps. Stamps can only be sent to other countries from London. The Royal Mail has offices around the world - including in New York, Chicago, Los Angeles, Sydney and Hong Kong - that will issue mailing permits for those countries who want to send mail there. Otherwise, all letters sent from outside the UK will require a standard postal rate. This applies even if you are sending items of low value such as magazines or books. Postcards are cheaper to send than letters. The cost of sending a postcard is based on the weight of the card and the level of service required. If you are sending a single card, then the cheapest option is by email. For multiple cards or larger packages, post offices near you are the best place to find competitive rates. Stamps can only be collected at post offices. There are some small independent post offices in major cities that accept stamps as payment but they are not recommended because they do not have access to many services that post offices located in more remote areas can offer. In fact, most of these small offices do not even have a lockable safe!