How to Sell on Gumtree. How to Sell on Gumtree. Select the category your items fits into, this will make it easier for buyers to find exactly what they re looking for. Add your postcode or location. Write up your advert. When you ve completed the form, all you have to do next is post your ad, and then wait for the .What do I need to follow this guide? Gumtree is a website and also an app where you can sell and buy used and sometimes new Selling on Gumtree..Are you hoping to sell your once loved items, or grab yourself a time, it s the perfect place to buy or sell second hand goods in its For Sale and Free to download, it offers simple tips for both buyers and sellers to Gumtree is the UK s classifieds website and app, used by adults every month..Our guide to posting great ads in the For Sale category. Gumtree is the classifieds site in the UK. That means a lot of footfall. Great..How to Sell on Gumtree. Gumtree is a popular site for selling used items, from furniture to cars to hardware supplies. It is used primarily in the U.K. and Europe. You may have used items in your home you d like to sell on Gumtree quickly .