OnBuy vs Amazon UK: Why Shopify Sellers Are Expanding to OnBuy

A factual comparison of OnBuy and Amazon UK fees, policies, and seller experience for Shopify merchants.

OnBuy vs Amazon UK is a comparison worth making before you decide where to sell next. OnBuy charges lower fees, doesn’t sell its own competing products, and has significantly less seller competition right now. Amazon has far more traffic. Which one wins depends entirely on what you’re selling and how you’re set up.

TL;DR: OnBuy charges lower commissions, doesn’t compete with its own sellers, and skips the pay-per-click ad model entirely. For Shopify sellers already managing their own fulfillment, it’s a compelling second channel. Here’s how it compares to Amazon UK, with real numbers. Connect your store with our Shopify OnBuy integration.

The Fee Comparison That Matters

Let’s start with the numbers, because everything else is just marketing unless the economics work.

Fee TypeOnBuyAmazon UK
Monthly subscriptionFrom 25 pounds/month + VAT25 pounds/month (excl. VAT)
Sales commission5-15% (category-dependent)8-15% (category-dependent)
Listing feesNoneNone (Professional plan)
Fulfillment fees (FBA)N/A (seller-fulfilled only)Varies by size and weight
Storage feesN/AMonthly + long-term surcharges
AdvertisingNone availablePPC campaigns (effectively required)

At first glance, the subscription costs look similar. But the total cost of selling diverges fast once you factor in what Amazon charges beyond the referral fee.

Commission Rates: Where OnBuy Pulls Ahead

Most OnBuy categories charge between 5% and 9% commission. Consumer electronics sits around 7%. Fashion and books are higher at around 15%. Amazon’s referral fees range from 8% to 15% across most categories, with a minimum of 25p per item.

For 2026, Amazon announced fee reductions averaging 15p per unit across European stores, plus referral cuts for clothing (down to 5% on items under 15 pounds, and 10% for items between 15 and 20 pounds). So the gap is narrowing in some categories, but OnBuy still comes in lower for many product types.

The real difference isn’t in the commission percentages alone. It’s in everything else Amazon charges.

The Hidden Costs of Amazon

If you use Fulfillment by Amazon (FBA), you pay pick-and-pack fees per unit, monthly storage fees per cubic foot, and long-term storage surcharges for inventory that sits longer than 180 days. These costs add up fast, especially for bulky or slow-moving products.

Then there’s advertising. Amazon’s search results heavily favor sponsored products. Most sellers report that advertising spend of 10-25% of revenue is needed to maintain visibility. That’s not a fee Amazon labels as “required,” but in practice, it is.

OnBuy has no advertising platform. Products rank organically based on price, seller rating, and delivery speed. You either compete on those metrics or you don’t. There’s no option to buy your way to the top of search results.

Competing Against the Marketplace

This is the structural difference that matters most. Amazon sells its own products. Amazon Basics, Amazon Essentials, and dozens of private-label brands compete directly with third-party sellers on the same search results pages. Amazon controls the Buy Box algorithm, the search rankings, and the product recommendations. And Amazon’s own products benefit from all of that.

OnBuy doesn’t sell anything. It’s a pure marketplace. The company makes money from seller subscriptions and commissions, period. There’s no incentive for OnBuy to disadvantage third-party sellers, because third-party sellers are the only sellers.

For Shopify merchants who’ve built their own brands, this matters. You’re not training a competitor by sharing your sales data with the platform.

Fulfillment: The One Area Amazon Wins Clearly

FBA is genuinely excellent infrastructure. Send your inventory to Amazon’s warehouses, and they handle storage, picking, packing, shipping, and returns. It’s expensive, but it works. Customers get Prime delivery speeds, and your seller rating benefits from Amazon’s logistics network.

OnBuy doesn’t offer anything equivalent. Sellers handle their own fulfillment or use third-party logistics providers. If you already fulfill your own Shopify orders, this isn’t a problem. You’re already doing it. But if your entire business is built around FBA, switching to OnBuy means rebuilding your fulfillment setup.

For Shopify sellers who ship their own orders, this is actually neutral. You’re already managing fulfillment. Adding OnBuy just means more orders to ship, handled the same way. With an OnBuy Shopify integration, those orders appear in your Shopify admin alongside your direct-to-consumer orders.

Audience Size: The Honest Trade-Off

Amazon UK dominates online retail. Its traffic dwarfs OnBuy’s 3.5 million monthly visits. If reach is your only concern, Amazon wins. It’s not close.

But reach isn’t everything. OnBuy’s customer base is growing at 50% year-over-year, they’ve reported 224% annual revenue growth, and more than half of UK customers make repeat purchases. The audience is smaller but engaged and expanding.

OnBuy is also pushing into Europe. They’ve launched in 12 EU countries with 308% sales growth during the beta phase. We cover this in detail in our article on OnBuy’s European expansion. For sellers already thinking about cross-border sales, that’s a runway worth watching.

Which Sellers Benefit Most from OnBuy?

OnBuy makes the most sense for Shopify sellers who:

  • Already handle their own fulfillment and don’t rely on FBA
  • Sell products with GTINs/barcodes (required for OnBuy listings)
  • Compete on price rather than on advertising spend
  • Want a second sales channel without the complexity and cost of Amazon
  • Sell in categories where OnBuy’s commissions are lower than Amazon’s referral fees

It’s not an either/or decision. Plenty of sellers list on both platforms. The question is whether the incremental revenue from OnBuy justifies the effort of managing another channel.

With the right integration, the effort is minimal. Your Shopify store stays your single source of truth. Products, orders, and stock levels sync automatically. That turns OnBuy from a second job into a second revenue stream.

The Bottom Line

Amazon is the bigger marketplace. OnBuy is the cheaper, fairer one. If you’re a Shopify seller with solid products, competitive pricing, and your own fulfillment workflow, OnBuy gives you access to a growing customer base without the fees and conflicts that come with Amazon.

Read our complete guide to selling on OnBuy from Shopify for step-by-step setup instructions, or check out the Shopify OnBuy integration to connect your store.

Frequently Asked Questions: OnBuy vs Amazon UK for Shopify Sellers