Shipping clothes from Canada to USA: what does the Certificate of Disinfection entail, where do I get it?

Shipping in smaller boxes means you're not a wholesaler or recycler who's going to regularly move large amounts of fabric for profit. The letter of that particular law wasn't really meant for you, and paying multiple layers of fees on principle just doesn't make sense.

Are you sure it applies to you shipping personal goods across the border? And not to used clothes marketers or distributors instead, like Goodwill? (I'm assuming that these clothes are yours.)

This came up in an old http://forums.ebay.com/db1/topic/Packaging-Shipping/I-Sold-A/520226541?messageID=514893075, where someone said that Goodwill disinfects and labels mattresses, and could do the same for clothing. Searching for Goodwill "certificate of disinfection" was amusing, as the first result was that same eBay thread, and the second was http://books.google.com/books?id=tPoNAAAAYAAJ&lpg=PA92&ots=_xg9lr5fSn&dq=CERTIFICATE%20OF%20DISINFECTION%20goodwill&pg=PA92#v=onepage&q=%22CERTIFICATE%20OF%20DISINFECTION%22&f=false. The fourth result was probably more useful, but provided without much context: http://www.suntrans.com/images/FUM.pdf, which can be found on http://www.suntrans.com/documentation.htm, linked as a "Fumigation Certificate." The PDF refers to Quarantine Law, and has places for the signatures of Director of Quarantine Station and Quarantine Officer Concerned. And that bit of information leads me to http://www.cdc.gov/quarantine/QuarantineStations.html, which has a lot more information.

Interesting. I have, and know quite a few people who also have, shipped clothes back to the US among personal effects, and the issue of obtaining a certification of disinfection never came up. In addition to filthy light thief's links, you might also see if you can find someone at an http://www.escapeartist.com/International_Moving_Companies/ who would offer you some practical advice on disinfection, even if you're not planning to use their service.

Have you tried asking Canada Customs/U.S. Customs? Surely they're the ones who would be looking for the certificate and thus would hopefully know something about it.

I work in a US Customs brokerage office, and I've never heard of a certificate of disinfection, and I've had several shipments of personal effects that have included clothing in the past. Every once in a while the USDA will flag a shipment for examination for foreign contaminants; they're really, really touchy about potential soil contamination, even if it's only something you personally are tracking into the country on the bottoms of your shoes. I'll see if there's anything I can dig up.

You may be able to fit everything into smaller boxes using those vacuum storage bags (the big ziplock bags that you suck the air out of with a vacuum. They are on infomercials and bed and bath stores). When we go on a trip we regularly use these, and they reduce the space that our clothes take up by almost half, depending on what the clothes consist of. This would allow you to use smaller boxes without necessarily using more boxes.

What The World Famous says. Avoidance is good in these things, because they save time, money and hassle. Also, you might be reading too much into the bureaucratese. If I read it correctly, they expect the clothing to be in some kind of dry cleaner's packaging, looking as if they were recently (dry) cleaned, with some kind of paper sporting the label "certificate" from a dry cleaner's or Rentokil saying that they disinfected it. Shouldn't be too hard.

You really should ask the US Customs people (https://help.cbp.gov/app/home). My cursory glance at used clothing only netted people importing for commercial purposes and w/r/t importing from used clothing from Europe. Disinfection is not listed, but paying duties on items is.