Blog / Supplier integration

How to integrate a supplier with Amazon: the real options based on your data

By the SellerKing team · Updated August 2026

"Integrating my supplier with Amazon" sounds like a single process, but it actually depends entirely on one question first: what way does your supplier currently give you to access their catalog, stock and prices? The answer determines whether the integration is a matter of days, or whether you first need to solve a root problem — the supplier simply doesn't share data in a structured way.

The real ways to integrate with a supplier

In practice, a supplier usually falls into one of these categories depending on how they deliver their information:

• API: the most robust option. The supplier exposes a service that can be queried for catalog, stock and prices in real or near-real time, and in some cases can also receive orders automatically.
• CSV or Excel: the supplier generates a periodic file (daily, or several times a day) with their catalog. It's slower than an API but perfectly viable if the update frequency fits your operation.
• XML or catalog feed: similar to CSV, but with a richer data structure, common among suppliers with large catalogs or complex product variants.
• FTP: the supplier drops files (usually CSV or XML) on a server that's accessed automatically, instead of downloading them by hand.

None of these options is "better" in the abstract — the right one is whichever your supplier actually supports and keeps up to date.

Why "my supplier doesn't have an API" isn't the end of the conversation

It's common to assume that without a modern API, integration isn't viable. In practice, a well-maintained CSV or XML feed can be automated just as well as an API — simply with a different frequency and access method. What genuinely blocks an integration is the supplier not offering any structured access at all — for example, if the only way to reach their catalog is a website built for manual ordering, with no export or feed of any kind.

What to check before assuming it's viable

Before assuming an integration will work smoothly, it's worth checking:

• How often stock and price are actually updated in that data source.
• Whether the catalog includes everything needed to publish on Amazon (EAN, weight, dimensions, category).
• Whether the supplier can receive orders back in a structured way, or whether that will stay manual even if the catalog is automated.
• Whether there's any volume, request or format limit that affects the integration.

This review is exactly what we do in a compatibility audit: it's not enough to know a supplier "has an API" or "sends an Excel file" — we need to verify that data actually works for automation, not just on paper.

What if your supplier isn't compatible yet

A supplier not having a clear integration path today doesn't mean automation is impossible: sometimes all it takes is asking them for a periodic export they already generate internally, or FTP access to a feed that already exists but isn't being used. Other times, specific development is genuinely needed. That's why every case is reviewed individually before promising a timeline or scope.