Real UGGs come in a sturdy box made of strong cardboard material. Some people say that the real box is a one-piece box with a flip top lid, but some people report also having purchased real UGGs that came in two-piece boxes with removable lids.
That piece of information is highly contested, but another part of the packaging that you can check is the plastic wrapper. The plastic that the boots are wrapped in should be made of thick, crinkly material with the words “UGG Australia” printed on it. The fake ones use low-grade thin plastic and almost always do not have anything printed on them.
Also check the care booklet, the authenticity card and other literature that the UGG boots are packaged with. They should be printed clearly on thick, high quality paper using quality ink — they should not be fuzzy, blurry, or appear scanned. In June 2007, UGG Australia stopped using white paper for these and switched to printing the UGG boots care booklet and other cards on cream-colored paper.
Real UGG boots have shoe inserts inside them to prevent them from becoming misshapen when stocked or shipped. Fake ones do not get the same careful handling and often do no come with shoe inserts.