Envelopes come in all shapes and sizes. The standard commercial envelope is 4 1/8 by 9 1/2 inches and anything above that is considered a larger-sized envelope. Many mail facilities use character-recognition equipment so it is essential to format addresses correctly in order to process them promptly. Where printed labels are used, a laser printer is recommended over an inkjet printer so that the quality remains intact throughout the machine-reading process.
Place the envelope with one of the longest sides closest to you. Start by placing your return mailing address at the upper left hand corner of the envelope. Using dark ink, print your name and below it print the number and street. Finish it off on the next line by adding your city, state and postcode.
Estimate one-third of the length of the envelope. Then estimate one-third down into the width of the envelope. Begin the address placement where the two points meet. Print the recipient's name parallel to the longest side of the envelope using dark ink. Directly underneath the first name or courtesy title, print the house or business number and street address. Follow up on the next line with the city, state and postcode.
Do not centre the elements of the address; be sure to begin each line at a uniformed margin width slightly left of the centre of the envelope. Write the city name in full, although you may abbreviate the state. Hyphenate the zip code, if you know the extra four numbers that follow, for example 02301-1911. If mailing abroad, always write the country name in full.
Omit commas or periods for optimum machine readability.
Avoid using unnecessary designs or graphics in the address area. It is possible to confuse the optical reading machinery.