What is the biggest box I can fit into a USPS drop box?

December 27, 2012 6:49 AM

What are the maximum dimensions (in each direction) of a box that will fit in a standard USPS blue drop box of the sort that you find on a city street corner?

I am ordering some boxes to use for mailing and although I usually take packages to the post office while it is open, I'd like to order the largest size that will give me the option of using USPS drop boxes after hours.

The maximum width is easy enough to measure and seems to about around 14" but the maximum height and depth are trickier due to the curved top and pivoting mail drawer.

Buying one of each of various sizes and trying them is not an option, since the type of boxes I am looking at are generally only sold in bundles of 25 or 50.

I'm looking for an answer from an authoritative source, not speculation—I can speculate myself.

I'm aware of the weight limits for stamped packages in drop boxes, but they do not apply to packages with printed labels from services like Endicia, so they are not relevant here.

I expected this information to be easy to find but I have not had much luck with Google or the USPS web site.

posted by enn to Grab Bag (12 answers total)

Somebody in this thread tested a 10x8x4 which fit. The 10" dimension could probably be longer, you can easily measure that. A 7" cube did not fit.

I think you can test without actually dumping the thing into the box — tie a string to it, and if the lid will nearly close it should go the rest of the way. The max is probably about 16x10x4 or 5.
posted by beagle at 7:37 AM on December 27, 2012

I just got off the phone with the USPS help line (800-275-8777). They either do not have he information or refuse to give it out. You will get what is on the website about 13oz. Her specific answer, after speaking with a supervisor, was that if it fits we will take it. It can be more than 13oz if using an online postage system rather than stamps. She guesses that there may be different sizes of blue collection boxes therefore they won't give a size. (I thought they were pretty standard one size, but who knows.)

I would add that part of the issue is what is already in the collection box. They could probably come up with a standard max dimension when empty, but if two people put that in before you, getting the pivoting mail drawer may not be able to fully extend if it is already partially full.

If it were me, to get the dimension when empty, I would measure the width as you did, the height of the opening which I think is accounted for in the curved top and then the depth of the drawer versus both the depth of the box front to back and the depth from drawer to bottom and come up with some sort of calculation.
posted by JohnnyGunn at 7:52 AM on December 27, 2012

Unless I am misunderstanding your question, you can't put boxes into USPS drop boxes, only envelopes, and only envelopes up to 16 ounces, at least according to the stickers placed inside the drop drawer. This is a post-9/11 measure, if I remember correctly. If you open up the drawer, you should be able to see the description of this limit.
posted by Blazecock Pileon at 7:53 AM on December 27, 2012

I've deposited small boxes in a drop box without a problem, but I also believe there is a weight restriction. The 13 oz. max for stamped packages is about 1st class vs. parcel post / priority / express mail, the latter categories requiring more than stamps. That's separate from the post-9/11 security-related weight limit, which applies regardless of what sort of postage or label you're using.
posted by jon1270 at 8:01 AM on December 27, 2012

FWIW your postal carrier will pick up any stamped or prepaid mail and or packages.
posted by Gungho at 8:02 AM on December 27, 2012

You can send boxes through drop boxes. The weight limit only applies to boxes (or envelopes) bearing stamps (and it actually says this inside the drawer if you read it closely); if you use an online postage service like Stamps.com or Endicia or Express 1 to generate prepaid mailing labels, you can send boxes that are heavier than the weight limit, presumably because you have to use a credit card to pay for postage this way and so the package is traceable in the event that you are mailing something that is a security issue. I have mailed numerous of packages with Express 1 postage up to several pounds through USPS drop boxes in the last few months with no problems.
posted by enn at 8:05 AM on December 27, 2012

I think the way to find out this answer is not through the USPS but through the manufacturer of the blue boxes themselves. If you can find out who makes them for the USPS, call them. They will know max size when box is empty.
posted by JohnnyGunn at 8:29 AM on December 27, 2012

If your local post office has an APC, you should be able to use that after-hours to send packages up to 15" wide X 12" deep X 6" high with max weight 70lbs.
posted by reptile at 8:31 AM on December 27, 2012

I found this link which are design specs for curbside mailboxes at residences. There is a name and phone number in the 2nd paragraph. I hesitate to list it here as it is 11 years old. If that is still a working USPS phone number, I would call that number and ask. This document is all about specifications for mailboxes. This person should either know or know who does know.

Also, if there are these sorts of specs for curbside manufacturers, I am sure there are specs for blue collection box manufacturers although I have not been able to find. Here is another government publication listing similar specifications.
posted by JohnnyGunn at 8:50 AM on December 27, 2012

Are you close to a mailbox? I'm almost positive the information is posted on them. Like Blazecock Pileon says, it's a post-9/11 thing.
posted by Room 641-A at 10:04 AM on December 27, 2012

I think this is actually a pretty tricky question because depending on the thickness of the package, the maximum length changes (due to the curved top of the box). I believe that the thinner of the two Priority Mail Flat Rate "Medium" boxes will fit, but not the thicker, cube-ish one, as a reference. This is despite the thinner one being larger, I think, in terms of volume.

The true maximum size package would be some sort of curved thing that would *exactly* fill the space created by folding down the door on the box, such that it would still drop in when closed. But I doubt that the dimensions for such a package are published, and it would be expensive to mail anyway.
posted by Kadin2048 at 7:57 PM on December 27, 2012

Belated thanks to everyone for their answers.

These dimensions are not posted on the mailboxes.

The nearby post office does have an APC but it is in the lobby and not accessible outside of the post office's open hours.

Kadin2048, that is a good point about the maximum depth varying with the height of the box. That would explain why the USPS will not give a straight answer to this question. I guess what I need to do is build mockups of the various mailer sizes and see which ones will fit.
posted by enn at 5:31 PM on December 29, 2012