To address a letter envelope correctly, follow these guidelines:

Front of the Envelope

• Recipient's address goes on the front, centered or positioned on the right side, parallel to the longest edge of the envelope.
• Write the recipient’s full name on the first line.
• On the next line, write the street address, including apartment or suite number if applicable.
• Then write the city, state (if applicable), and postal/ZIP code on the same line.
• For international mail, add the country name on the last line.
• Leave the upper right corner free for the postage stamp or postage indicia

Upper Left Corner (Front) or Back of Envelope

• Write the sender’s (return) address in the upper left corner on the front or on the back flap of the envelope.
• Include the sender’s full name, street address, city, state, postal code, and country.
• The return address is important so the mail can be returned if undeliverable

Additional Tips

• Write addresses parallel to the longest edge of the envelope.
• Use a pen and clear handwriting.
• Do not write on the back of the envelope except for the return address if preferred.
• Leave space around the edges to avoid cutting off any part of the address.
• For envelopes with windows, the recipient’s address is visible through the window, so ensure the letter inside is correctly positioned

This format ensures safe and efficient delivery of your letter.