How do I send priority mail?

To send a letter as priority mail, you need a priority stamp.

To be sure that your priority delivery arrives the next workday, you must put it in a red mailbox before the last collection or drop it off at a Post Office or Post Point before 16:00.

Only a priority stamp guarantees that your letter is delivered the next workday. Writing 'priority' on an envelope with a non-priority stamp does not count.