The last four numbers on ZIP codes.......

[shawmarki]

Is it neccisary to look up and add those last four numbers (used for PO boxes) after the first five numbers of the Zip code?

[myboardid · Accepted solution]

No, if you are printing your postage online.  The postage printing sections of eBay/Paypal and other postage companies add them automatically. 

[postingid2017]

Those last four digits are called zip + four and have been around since the 60s (1963 to be exact).  I always use it on my mailing address and when I ship items.  I mainly now use USPS to ship so the + 4 is automatic on their site.   It is supposed to assist in sorting and/or delivery of the mail.  Most don't use it, but no, you don't have to.

One of the attorneys that I worked for (fresh out of law school) flipped because I used the +4 and even had the nerve to print out the bar code LMAO!  I had to explain to the 'newby' a couple of things including not sending a Motion to Court with pages reading like a book.  He told me to send it out like that and I complied.  The Judge reamed him a new one for that 😉   Judges and their Clerks don't like that 🙂

[duchess-at-speakeasy]

The full 9-digit zip code identifies a specific address, not just a general geographic area, so it is very useful in automated sorting.  Mismatched numbers are easily flagged and corrected.  Sometimes, PO boxes are assigned an exclusive zip code that is not on any map.

In general, adding the 4-digit suffix reinforces the accuracy of an address.  For PO boxes, the suffix generally is the box number preceded by one or more zeroes although format exceptions do exist.

Online prepaid labels include the necessary 9-digit zip code.  If you are manually preparing a label, it's always a good idea to look up the information to verify the accuracy and assure the completeness of an address, PO box or not.

~~C~~ 

[partial*eclipse]

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@postingid2017 wrote:

Those last four digits are called zip + four and have been around since the 60s (1963 to be exact).  ...

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ZIP Codes were introduced in 1963.  ZIP+4 was twenty years later, in 1983.

[muttlymob]

The full 9-digit zip code identifies a specific address, not just a general geographic area,

The +4 does not necessarily indicate a specific address.  It may indicate the side of a street, eg, all addresses on one side of a street will have the same +4.  Or it may indicate some other more general location than a single address.

[southern*sweet*tea]

http://faq.usps.com/?articleId=221652

The nine digits of a ZIP+4 code (e.g.,12345-6789) may be grouped as follows: [123] [45] [67] [89]

• [123] :  Sectional Center or Large City
• [45] : Post Office facility or Delivery Area
• [ - ] : The required "dash" or "hyphen" separates the first five digits from the last four digits; the +4
• [67] : Sector or Several Blocks
• [89] : Segment or One Side of a Street

[duchess-at-speakeasy]

The last 4 digits are quite specific.  For example, my apartment building is identified by 4750.  The building next door, on the same side of the street, may or may not have the same 4 digits, depending on how wide the range of house numbers is. However, the 4 digits that I use for my specific address apply to a bank of 4 apartment mailboxes (out of 32).  I'll still get my mail if someone uses 4750 or only the 5-digit zip code, but narrowing the choices to only 4 apartments certainly helps sorting accuracy! ~~C~~