This issue is especially relevant in situations where windowed envelopes are used (thus, the address printed in the correspondence is also the same address read by USPS for delivery processing). Why NOT two spaces? Why not write addresses in the body of the letter that can easily be copy/pasted as USPS-formatted delivery addresses? Even if it’s on one line in the body, why not use an address in the body that, with the addition of some line breaks, is ready to be used as a USPS-formatted delivery address? Also, a USPS-formatted address in the body can be more easily OCR’ed from the letter and used as a delivery address. This is too easy for all of these repetitious questions and postings… If you need to mail to an address outside of the USA, check the Internet for that country’s instructions. If you want the least likelihood of UPPS mail issues, address the envelope the way they request. Do whatever you like/learned in school/think is proper on the inside address. This has nothing at all to do with grammer, punctuation, how you think it looks, or keeping your pinky finger in the air as you sip. You can just copy/paste and be done with it. It will return the address, properly formatted (ALL CAPS) for the Post Office, with the ZIP Code and +4. The second is a page that looks up zip codes if you provide a enough of a real address-that is to say enough of the correct address for a real location. Then city, then 2-letter state, then ZIP and +4 (The abbreviations are also on the UPSP site) Then street address including STE, #(Yes, this is ok to use), SP, APT, etc. Basically, it says “all caps, no punctuation unless it is actually a part of a name or address, use all addressing abbreviations, start specific and end general.

The first gives details on how to address an envelope.

Envelope address template apartment