I order products that are shipped to me in cardboard boxes. If the box looks nice, I save it for mailing out large/bulky orders. Many of you may reuse cardboard boxes too.

Make sure that you remove any shipping labels on the box that contain any kind of bar code information. That is because the USPS sorting facilities read the bar code labels that the USPS attaches to packages. If they found an errant bar code on there, it’s going to try and read it as a tracking number.

Sometimes the labels are difficult to remove or the bar code is printed on the box itself. In these cases, I use a thick black marker and just write over the bar codes to make it a large black box, which the USPS readers won’t be able to recognize.

Also, if you try using boxes that have printing indicating that alcoholic beverages are inside, those boxes are not acceptable either. Even though there may be no alcohol inside, the USPS still will not accept anything mailed in those boxes. Likewise, any boxes that contain markings indicating that hazardous materials are inside are also not acceptable for mailing.

Reusing cardboard boxes is fine. You just have to watch out for a few things that could cause the window clerk to reject your package.