The web can be a good place to get a bargain, but there are warnings people could be tricked into buying fakes.
The people who monitor shopping have found dodgy sites claiming to sell things like big brand trainers, which later turn out to be fakes
Lots of those sites use "co.uk" in their address, which could lead people to think they're trustworthy, even though they're not based in Britain.
They want people to take extra care to check up on who they're buying from.
Because the fakes include thing like hair straighteners, they can actually be dangerous.
Genuine goods have to go through strict safety checks before going on sale, which the fakes do not.
If you think a site might be a fake, trading standards officers say you could investigate them by doing these three things:
• Searching for any user reviews of the site;
• Double clicking on the padlock symbol in the corner to reveal details about the company that registered the site;
• Trying to connect the site to the real world by finding phone numbers or UK addresses.