How long does it take for a letter to arrive after being sent?

How long will it take for a letter from UK (sent by Royal Mail) to arrive in Arizona?

• I am sending a few pages and a postcard in an envelope from UK (near London) to Arizona by Royal Mail regular air mail. How long will it take before the letter arrives?

• Answer:

  Royal Mail usually says the target is five days officially, but thats based on their own estimates, and may not necessarily accurately represent the other companies used along the line (in this case the airline and the US Postal Service). It usually takes RM approximately a day and a bit to get the mail to an airport and on the plane, and from then on its in the hands of the USPS. I've heard of people in the main eastern US cities getting their airmail in as little as three days, but then the western US cities and rural areas may take up to six days, so I suppose it depends on how close the address is to a big city, and the distance it must travel. Sadly with regular mail, there can be no definitive answer.