Kathleen in PA  says:
2 years ago

The country is divided into 9 REGIONS, going from east to west, numbered 0 - 9.    Within each region are GEOGRAPHICAL AREAS, similarly numbered 0-9.  The third number represents the SECTIONAL POST OFFICE within that geographic area.

Then the last two digits are for EACH post office, and are assigned ALPHABETICALLY, by city name.

The + 4-digit number seems to indicate: pos 1-2:  Carrier Route.  Pos 3-4, East/West or North/South side of the street. It can also indicate a Post Office Box number.

There is also an additional +2 numbers, that I 'think' are the last two positions of the house number.

Ideally, these 12 numbers alone (without address) would get a parcel to the correct house, assuming the post office uses all 12 numbers.

Additional comment:  There is to be NO COMMA between the city and state, on addresses:  100 Main St.  AnyCity   NY  nnnnn-nnnn-nn

Kathleen in PA  says:
2 years ago

No problem! I was 'around' when they started, and I can't 'let go' of something that 'should' make sense, ha ha. The first part of the ZIP code came from a classmate of mine, whose father was Post Master in our hometown, and actually made the suggestion of using numbers. Don't know if it was HIS suggestion that got the ball rolling or not, but probable. One **correction** I made: not even/odd, but East/West or North/South side of the street, for last two digits of the +4. I certainly couldn't find any explanation on the USPS site!!

SweetiePie  says:
2 years ago

Had never looked into this topic, but thanks for sharing this info. I answered a request about where to buy stamps, so our hubs have something in common :).

dutch84  says:
2 years ago

You rock! I have wondered about this.

What about area codes. Do you know how those are chosen?

glassvisage  says:
18 months ago

What a great idea for a hub!

Kathleen in PA  says:
18 months ago

Thanks, everyone!  I had 'fun' figuring it out - really!  Numbers have always interested me.

Violette, you must have had fun w/the DB! I must "assume" that the odd/even rule is true, then, instead of N/S & E/W, due to pgmg experience.

I recently created one in ACCESS for my high school class (won't tell you which year, ha ha). Didn't have opportunity to work on Data Bases on Mainframe through. - although everything ELSE!

I haven't looked into the Area Codes yet...there are new ones cropping up all the time, and some have been split off due to overload/population.  Probably 'arbitrary', ha ha. Mine is 717, next-door neighbor's is 975 - Go Figure!

HEY, IT'S CONTEST TIME!!!

                         Go to your local Post Office, and TRY to get an answer on the ZIP CODE 'rule'!  Mine just said "We don't use the +4, and he never heard of the added two digits!!!                                                                     

SweetiePie  says:
17 months ago

This would be a good article for kids that are learning how to mail letters and about the US Postal service. I better go mixx it for you.

hamil331  says:
8 months ago

I never knew there was this type of info in a zip code...thanks