In fact, almost a fifth (18 percent) of those polled are sitting on between £226 and £500 worth of belongings that are just gathering dust.
And with more than half (52 percent) saying they are under significant financial strain, and 59 percent looking for ways to make money outside of their day job, selling their pre-loved items could be a handy side hustle.
The study, commissioned by Gumtree as part of its inaugural “Circular Economy Report”, found that the wardrobe could be a good place to start, as the average Brit is holding onto six unwanted items of clothing.
And those in need of a bit of extra cash also typically have six unwanted objects in the “films, books, and music” category, as well as three unused video games or consoles cluttering up their homes.
Meanwhile, 17 percent are planning to try and sell an old mobile phone that is stashed away in a drawer or cupboard, while 15 percent hope to part with their outgrown baby or children’s gear.
And Brits aren’t just looking to make some money from old items, but also hope to save money on any new items coming in to their homes – as 49 percent plan to buy pre-loved, secondhand objects in the future.
The category in which Brits would be most willing to buy second-hand is entertainment, with 37 percent likely to purchase pre-owned DVDs, films, music, or books.
This was followed by clothes, shoes, and accessories (31 percent), and home and garden items (20 percent).
And the growing popularity of “recommerce” is not only driven by money-saving and a hunt for bargains – many also see it as a way of reducing waste.
Nearly half of green-minded Brits (45 percent) agreed that taking part in the secondhand economy is an effective way of becoming more sustainable.
The top three reasons for selling items second-hand were to give them a new life elsewhere (57 percent), to declutter (52 percent), and to save items from landfill (49 percent).
Kate Hardcastle, MBE, business expert and broadcaster, said: “It is great to see how shopping secondhand is no longer seen as something to be ashamed of.
“In fact, saving money, items from landfill, and as a result, the planet, is fast becoming a badge of honour.”
Encouraging everyone to get involved, she advises new sellers to market their objects with a photo and some well-chosen words.
She added: “All you need is an unwanted item, a picture, and to give your item a story the next owner can invest in.”
And the research found that many people will already have bought or sold some secondhand items – as 38 percent of those polled are members of local neighbourhood groups, either digitally or in person, that post unwanted items to sell or give away.
This figure rose to 45 percent in the group-trading hotspots of Birmingham and Bristol – while Manchester has 41 percent of people involved in this thriving secondhand scene, London has 40 percent, and Southampton is also above average, on 39 percent.
Hannah Rouch, chief marketing officer at Gumtree, said: “Gumtree has been committed to a recommerce since its launch in 2000, enabling communities to share more and waste less, and building a culture of conscious consumerism.
“Our report shows that the public are now taking matters into their own hands – and whether that’s to protect the pennies or the planet, the world of recommerce is well and truly hitting the mainstream.”