WooCommerce to OnBuy Integration

Sell on the UK marketplace that never competes with its own sellers — straight from WooCommerce

Overview

OnBuy is the UK's fastest-growing challenger marketplace, founded in 2016 on a simple promise: it never sells its own products and never competes with its sellers. With more than 8 million monthly visitors and over 35 million listings, it has become a credible third channel alongside Amazon UK and eBay UK — but without the platform-owned private labels that undercut independent sellers on Amazon. For WooCommerce merchants targeting British buyers, that level playing field is the headline reason to add OnBuy.

The economics reinforce the appeal. OnBuy's category commissions of 5–9% are among the lowest of any major marketplace, well under Amazon's 8–15% and eBay's 10–13%. Electronics sit at roughly 5%, Home & Garden around 7%, and Fashion & Accessories near 9%. On top of commission there is a payment-processing fee of about 2% and a monthly subscription that starts at £19/month (Standard), £39/month (Premium), and £79/month (Unlimited). Even with all three components, total cost per sale typically lands below Amazon and eBay.

Marqetir connects WooCommerce to OnBuy through the native WooCommerce REST API rather than a WordPress plugin. You generate a key pair in your WooCommerce settings, paste it into Marqetir, and the integration reads your catalog, matches products to OnBuy by EAN/GTIN, and publishes listings — with nothing installed on your WordPress site to update or break. This keeps your store fast and avoids the plugin conflicts that often come with marketplace add-ons.

Once live, the connection keeps everything in step. Prices convert from your WooCommerce base values into GBP, inventory syncs in near real time so you never oversell, and OnBuy orders are written back into WooCommerce as native orders for fulfillment. Because OnBuy is English-language and UK-focused, listing localization is straightforward compared with continental marketplaces — your existing product content usually needs only light optimization rather than translation.

For sellers worried about platform concentration, OnBuy is a practical diversification play. Its buyers are deliberate comparison shoppers who chose the platform for better deals, and its catalog still has gaps in many categories, so well-listed WooCommerce products can gain visibility faster than on saturated marketplaces. Running OnBuy alongside eBay or Amazon spreads risk while OnBuy's low fees protect margin on every order.

Before You Start

  • A WooCommerce store on a self-hosted WordPress site with REST API access enabled
  • An OnBuy seller account on a paid plan (Standard from £19/month)
  • A UK or EU-based registered business
  • A UK VAT number if you are above the VAT registration threshold
  • EAN/UPC/GTIN barcodes for all products (OnBuy matches offers by barcode)
  • The ability to ship to UK addresses within stated delivery timeframes
  • Compliance with UK product-safety rules and, for EU dispatch, customs handling

Key Benefits

No marketplace competition — OnBuy never sells its own products
Lower fees than Amazon UK and eBay UK — 5–9% commission
Plugin-free REST API connection to WooCommerce — no WordPress overhead
Fair Buy Box that doesn't favour platform-owned listings
Automatic GBP pricing generated from WooCommerce base prices
OnBuy orders sync back into WooCommerce as native orders
English-language, UK-focused — minimal listing localization required

What Syncs Automatically

Catalog sync

Products and variations are read from the WooCommerce REST API and matched to OnBuy's catalog by EAN/GTIN, attaching to existing listings or creating new ones.

Inventory sync

Stock updates flow both ways in near real time, so an OnBuy sale reduces WooCommerce stock and a WooCommerce sale deactivates the OnBuy listing at zero stock.

Price sync

WooCommerce base prices convert to GBP using your rules; any price change in WooCommerce propagates to the corresponding OnBuy listing.

Order sync

OnBuy orders are created as native WooCommerce orders so fulfillment, invoicing, and reporting stay in one system.

Returns sync

Return and cancellation events on OnBuy are written back to the matching WooCommerce order to keep records aligned.

How to Connect

  1. 1

    Generate WooCommerce REST API keys

    In WooCommerce go to Settings → Advanced → REST API, create a Read/Write key pair, and paste it into Marqetir. No plugin is installed on your WordPress site.

  2. 2

    Create and verify your OnBuy seller account

    Register as an OnBuy seller and choose a plan (Standard from £19/month). Onboarding requirements are light compared with Amazon.

  3. 3

    Connect OnBuy to Marqetir

    Link your OnBuy seller account using its API credentials so Marqetir can publish listings and pull orders.

  4. 4

    Match products by EAN/GTIN

    Marqetir matches your WooCommerce products to OnBuy's catalog by barcode, attaching your offer to existing product pages and creating new ones where needed.

  5. 5

    Set GBP pricing and UK shipping

    Define GBP prices from your base values (rules or fixed), configure UK delivery options and timeframes, and let AI tidy titles and descriptions for UK buyers.

  6. 6

    Go live and manage orders in WooCommerce

    Publish your listings. Inventory and prices stay synced automatically, and every OnBuy order lands in WooCommerce as a native order to fulfill.

Features

WooCommerce REST API connection — no WordPress plugin to install or maintain
EAN/GTIN product matching for fast onboarding to OnBuy's catalog
Fair marketplace — no platform-owned product competition
Automatic GBP pricing derived from WooCommerce base prices
WooCommerce variable products mapped to OnBuy product options
Real-time inventory and price sync to prevent overselling
UK carrier support (Royal Mail, Evri, DPD) for delivery options
OnBuy orders, returns, and cancellations synced back into WooCommerce

Who It's For

Escaping Amazon's own-brand competition

WooCommerce sellers tired of competing with Amazon's private labels move volume to OnBuy, where the platform never lists against them and the Buy Box treats every seller equally.

Protecting margin with the lowest UK fees

Electronics sellers especially benefit from OnBuy's ~5% commission versus Amazon's 7–8% and eBay's 10–12%, keeping more of every sale even after the ~2% payment fee and subscription.

Adding a UK channel without translation work

Because OnBuy is English-language, WooCommerce stores already selling in the UK can list with light optimization instead of the localization that continental marketplaces demand.

Diversifying beyond a single marketplace

Sellers running mainly on eBay or Amazon add OnBuy to reach comparison shoppers and reduce dependence on any one platform, with catalog gaps that reward well-listed products.

More on selling on OnBuy

Related Integrations

Frequently Asked Questions

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