Amazon Shopify Integration (and eBay)
Amazon Shopify integration, plus eBay: sell on both marketplaces from one Shopify catalogue with stock kept in sync. For most stores Shopify Marketplace Connect is the right start, and we will tell you if it is enough. When it is not, we build a custom connector on Amazon's Selling Partner API, the Shopify Admin API and your ERP or accounting system's API. That connector covers Fulfilment by Amazon (FBA) and 3PL stock reconciliation, pricing rules, order sync into Shopify and settlement sync into that system. Scoped in writing.
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- App-first advice
- Senior engineers only
- London based
Our Amazon and eBay Shopify integration process
- Check if the app is enough. We start with Shopify Marketplace Connect, Shopify's own app for Amazon and eBay, plus Walmart and Target Plus in the US. If what it syncs covers your catalogue and fulfilment, and your accounts do not need settlements posted line by line, we help you set it up and stop there. Custom work only starts where the app runs out.
- Map listings and stock. We match Shopify products and variants to marketplace listings, and map which Shopify locations feed each marketplace. On custom builds, stock held in Amazon FBA, your warehouse and a 3PL is reconciled, so the stock each channel shows stays close to the stock actually available to fulfil its orders, and drift between Amazon and Shopify is flagged by a daily reconciliation job.
- Build the connector. Where the app falls short, we build on Amazon's Selling Partner API and the Shopify Admin API, plus your accounting system's API for settlements. That covers order import, fulfilment and tracking updates, inventory and price feeds, and settlements posted to Xero, QuickBooks or NetSuite. Writes are idempotent, so a retried job does not create a duplicate order.
- Monitor and support. On custom builds, a reconciliation job compares Amazon and Shopify orders and stock, and alerts on drift and failed feeds. We agree a support window in writing before the engagement closes.
What the Amazon and eBay integration includes
- A straight first answer: Marketplace Connect set up and configured when it covers your needs, custom work only when it does not
- Product and variant mapping between Shopify, Amazon ASINs and eBay listings, with Amazon bundles and multipacks handled on custom builds
- Inventory sync between Shopify and the marketplaces, and on custom builds Amazon FBA and 3PL stock with buffers that reduce the risk of overselling
- Amazon and eBay orders synced into Shopify, and on custom builds fulfilment and tracking sent back to Amazon through the Selling Partner API
- On custom builds, Amazon pricing rules on top of listing sync, so marketplace fees and margins are reflected in the price
- On custom builds, Amazon settlements and fees posted to Xero, QuickBooks or NetSuite so Amazon revenue reconciles
- On custom builds, idempotent writes and a daily Amazon reconciliation report, so Amazon orders and stock do not drift silently
Amazon integration timeline
Scoped per catalogue
Setting up Marketplace Connect is the quickest option. The length of a custom Selling Partner API build with FBA stock, pricing rules and accounting sync depends on catalogue size and how many systems are involved. We confirm the window in writing once the mapping is agreed.
FAQ
How do I set up a Shopify integration with Amazon?
Use Shopify Marketplace Connect, Shopify's own app. It connects a Shopify store to Amazon and eBay, plus Walmart and Target Plus in the US, and syncs listings, orders and inventory. It is free to install. The first 50 marketplace-synced orders a month are free; after that Shopify charges 1% per synced order, capped at $99 a month and billed in USD. Amazon's own selling fees are separate.
When do I need a custom Amazon integration instead of the app?
When your setup goes beyond what the app syncs. Typical cases, which we check against the app first: stock split across FBA, your own warehouse and a 3PL with channel-specific buffers; pricing rules that react to fees or competition; bundles that map to several Shopify SKUs; and settlements that must post line by line to an ERP or accounting system. Those builds use Amazon's Selling Partner API.
What is the Amazon Selling Partner API?
The Selling Partner API (SP-API) is Amazon's REST API for sellers and vendors. It gives access to orders, shipments, inventory, listings, pricing, financial reports and notifications, and it is what our custom Shopify to Amazon integrations are built on.
How does eBay and Shopify integration work?
For most stores, eBay and Shopify integration can run through the same Marketplace Connect app, so eBay and Amazon listings, orders and inventory sync with the same Shopify store. When a custom build is needed, we scope the eBay side separately after checking what eBay's APIs expose for your listings.
How do you stop overselling across Shopify, Amazon and eBay?
By deciding which stock each channel can see. Marketplace Connect keeps inventory in sync with the marketplaces. On custom builds, we add buffers on fast-moving lines, read FBA stock from Amazon rather than assuming it, and run a daily reconciliation job that compares Shopify with Amazon, so drift is flagged at the next daily run instead of going unnoticed. Custom eBay checks are scoped separately.
How much does a Shopify Amazon integration cost?
If Marketplace Connect covers your needs, the integration cost is Marketplace Connect's per-order fee (the first 50 synced orders a month free, then 1% per synced order capped at $99 a month) plus the cost of a short setup; Amazon's own selling fees are separate. A custom Selling Partner API integration is quoted in writing after we map your catalogue, fulfilment and accounting systems, because those decide the size of the build.
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