Overview
OnBuy is a fast-growing UK-founded online marketplace that sells a wide range of products from third-party sellers, from electronics and home to toys, beauty and sports. It never sells its own products, so it does not compete with its sellers. Since 2025 it has expanded quickly across Europe and now operates in more than 20 countries. For a brand looking for an alternative to Amazon and eBay in the UK and Europe, OnBuy is one of the most interesting challenger marketplaces.
Who is behind OnBuy
OnBuy was launched in November 2016 by Cas Paton, its founder and CEO, and is based in the UK. It has a lean team of around 100 people. OnBuy reported more than GBP 150 million in UK sales in 2024, with sales of GBP 44 million in the fourth quarter alone, and around USD 200 million in gross merchandise value in 2025. The Financial Times named it Europe's fastest-growing e-commerce business. In 2025 OnBuy acquired the Comet brand and is relaunching it as a UK electronics marketplace.
Expansion into Europe
In September 2025 OnBuy opened to sellers in Germany, France, Spain, Italy, the Netherlands, Belgium, Austria, Greece, Finland, Portugal, Ireland and Slovakia, after a test phase in which it reported 308% sales growth. It aimed to be active in 20 European markets by the end of 2025 and is now live in more than 20 countries, with plans to enter the US. OnBuy aims to reach GBP 1 billion in GMV within three years.
Cashback for shoppers
OnBuy introduced a cashback loyalty programme in 2023, describing itself as the world's first cashback marketplace. Shoppers earn cashback on every purchase, which they can spend again or withdraw, which helps OnBuy bring customers back.
How selling on OnBuy works
- Commission-based. OnBuy charges commission on sales, with transparent fees and no hidden costs, according to the company.
- A shared catalogue. Products are listed in OnBuy's catalogue, and sellers add their offers to them, so accurate EANs are essential.
- Several countries from one account. Sellers can reach the UK and OnBuy's European sites, with local currencies and languages.
- The seller fulfils orders and must meet OnBuy's delivery and service standards.
- Integration through OnBuy's API or multichannel tools.
Why OnBuy matters for brands
OnBuy offers a growing audience, fewer sellers per product than the largest marketplaces, and a fast route into many European countries. It is a useful way to diversify beyond Amazon and eBay.
How eBrands looks at OnBuy
eBrands sells on OnBuy in the UK and Germany and works with brands on marketplaces across Europe and North America. If you want to see how OnBuy could sit alongside the channels you already use, we are happy to talk it through.
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