Ugg boots are available in a large number of countries and they are extremely popular
with a lot of people and when something sells in such numbers people are always going to try and manufacture copies to sell. You are lucky though in that there are a few things you can look at which are going to tell you if you have genuine uggs or indeed a pair of fakes in your hand.
The first thing to check is where you are buying them from and only use a reliable company. You are going to get the real article when you buy from an established big name company so at least then you do not have to worry about it.
Spend time actually checking the sole as the real one is flexible whilst the fake is more solid. Also check the sole because on the real ones it should go from heel to sole nice and smooth whilst on the fake there is a ridge so it is easy to spot.
The actual sole itself is very thick on the genuine article but the fakes are a lot thinner because the people are trying to save money where they can. You should also be able to feel a difference in quality in the entire boot between a fake and a real one from the stitching down to the actual fur that is used.
The fake uggs use a synthetic fur which is nowhere near as soft and good to touch as the real sheepskin fur in the genuine uggs. You can also find that the fake fur can be basically ripped off quite easily due to the poor quality of the stitching that is involved.
Last of all is of course the price to alert you to what is fake and what is real. You may think that you are getting a good deal but often all is not what it seems so instead of trying to be clever and save a bit of money in actual fact you have thrown it all away due to not buying from a reputable company.