US Postal Service Mail Box

US Postal Service Mail Box – Regulation Mailboxes

A regulation US Postal Service mail box is specified in the Domestic Mail Manual created by the US Postal Service.  Regulation US Postal Service mailboxes can be purchased online from many different retailers.

Before purchasing your mailbox online, make sure it is US postal approved.  Curbside mailboxes are available in three sizes: -

  • Small T1 (C1) size is approximately 5 inches wide by 6 inches tall and 18 ½ inches long.
  • Medium T2 (C2) size is approximately 6 inches wide by 7 inches tall by 19 inches long.
  • Large T3 (C3) size is approximately 8 inches wide by 11 ½ inches tall by 22 ½ inches long. 

The “T” stands for Traditional and the “C” stands for Contemporary. The dimensions reflect the minimum interior size. 

Post mount boxes should be positioned 6-8 inches from the curb and approximately 42-46 inches high measured from the lawn to the top of the installed mailbox, not the top of the post. If the post has a vertical arm, the arm should not extend any closer than 6 inches from the curb.

When installing your new set, make sure your set complies with these regulations.  Be cautious when building your own mail box and post. Approximately 100 motorists are killed yearly in collisions with mailboxes. Some posts are mounted in concrete or constructed of indestructible materials.  In a collision, a motor vehicle can be severely damaged and its occupants injured or killed.

The U.S. Postal Service does not govern wall mount boxes, however, you should notify your local mail carrier before installation to ensure proper placement of the mailbox and check for any local codes or regulations governing placement of the box.  The product should operate easily and nothing should obstruct the opening and closing of the lid. Also check with your home owners association to see if they have any association by-laws which you need to comply with.


  1. gary moore says

    is there any law on parking in front or blocking the crub side mail box. our neighbor parks there car next to our box. making our mail carrier have to get out of her truck to deliver our mail.

    • tom mcqueary says

      tom mcqueary kon-tiki ter. portorange fl. 32129 is a car or truck allowed to park curbside and block delivery of mail where the mail person cannot deliver mail with out gitting out of his mobil- thank you

  2. Tim says

    Please, Lets Get Some kind Of Law Passed In California, I’v Had It With These People Who Do Not Respect The Mail Box Of Another..Parking Right In Front Of The Mailbox. Now I Understand The Mail Carrier Doing a Good Job. For Some Disrespectful Person To Block On Purpose On The Street And Could Care Less If You Get Your Mail Or Not…Lets Help Our Mail Carriers At Least During The Delivery Hours…..

  3. Darlene says

    Our mail box is across the road from our house. Can we move our mail box on our side of the road. There is a lot of traffic on the road. some time I need to waite long time to cross. The cars are going about 50 miles an hr. It’s getting to dangerous.

  4. jbc says

    USPS mailbox, wall mounted for triplex. Lock not fuctioning on individual unit. To whom is this reported as the mail deliverer apparently is not aware or ignores malfunction.

    Would appreciate reply ASAP as mail door flopping in the wind.


    • Dana Lee says

      The post office does not purchase or maintain mailboxes or collection boxes that are common for apartments. That is the responsibility of the home owner or property owner.

  5. Cliff Lopes says

    Our nieghbor cluster mail box site was broken into and vadalized. It may be weeks until it is repaired. We currently have to go to the Post Office to get our mail. Can we install our own curbside mail box in front of our home to have the USPS deliver our mail there in the mean time. Is it a law?

  6. Eric Huge says

    Just moved in to a townehome in Naperville, IL. What rights do I have with regards to collecting my own mail?

  7. Kos says

    I don’t get what the big deal is?!? Can’t the mail man simply stop being lazy and get off there ass and walk the 2feet around the vehicle to the mailbox? I mean seriously!! Isn’t the postal service moto something like through rain,sleet,and snow or heat or something like that right?! I don’t remember hearing a OH!! Unless there’s a car in the way!!! Maybe california needs to take a time warp back to when they used to have to walk around from block to block house to house!! That would really help the situation wouldn’t it!!? Don’t get me wrong Ive got nothing against the postal service but c’mon!! It’s there job! I could only imagine if my job was to let’s say make copy’s of something and when people came to me with( Hey!! Where’s my copy of today’s stuff and I said oh!! I’m sorry there was a stack of chairs in the way of me safely printing them up today!) I don’t think I’d have that job for much longer wouldn’t you agree? And another thing they chose this job as we all chose ours so just like we deal with all of our day to day mishaps and still manage to work around them and get through the day should’nt they?!?


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