Amazon, eBay, OLX: get ready before the integration exists

On our integration scorecard, Amazon, eBay and OLX all sit as planned — 📋, not ✅. We’ve named the intended API in each row: a marketplace adapter via Amazon SP-API, one via the eBay Sell API, and OLX listed simply as a marketplace adapter with no technical detail yet. None of the three works today, and we’d rather say that plainly than let a roadmap row read like a shipped feature. The marketplaces running in production right now are Allegro and ERLI.

One orienting note for readers outside Poland, since OLX looks like the odd one out: it’s a Polish and CEE classifieds platform that has grown a real marketplace layer for business sellers — company profiles, bulk listing import, paid visibility. OLX’s Polish business site reports 17 million monthly active users. For a merchant selling into Poland it’s a volume channel, not a small-ads board.

Here’s the thing we keep running into when an agency asks us about the Amazon timeline: entering a new sales channel rarely stalls on technology. It stalls on a document with the wrong date, a missing EAN across half the catalogue, and configuration that has to be repeated per country. All of that is doable today, without an adapter and without an integration. And if it isn’t done, the finished adapter sits idle anyway, because the account never clears verification.

So this is the client-prep checklist we’d hand over before the integration exists — with the facts taken from each platform’s own documentation.

Amazon Seller Central verification: the documents checklist

Registering in Seller Central is a matter of hours. Amazon Seller Central account verification is a different story. Amazon’s Polish registration guide lists what you need on hand (the US guide’s list differs slightly, so check the one for the marketplace you’re registering on):

• a government-issued identity document (usually a passport),
• proof that the business is trading (for business sellers),
• proof of address — a bank statement or utility bill,
• proof of your relationship to the company, e.g. an employment contract or share certificate,
• a credit card: Visa, Mastercard or American Express,
• business bank account details.

The first trap is a date. The bank statement used for verification must have been issued within the last 180 days. The same 180-day window effectively applies to the company registration document: if it was issued more than 180 days ago, Amazon will ask for alternative documents. A statement from last year won’t pass.

How long does it take? Amazon says most verifications finish “within a few business days”, and identity verification “usually takes three business days or less”. That’s the optimistic version, and it describes the case where everything matches. In practice the clock stops on inconsistencies: a company name written one way on the registration document and another way on the bank statement, an address with a unit number in one document and without it in another, an abbreviated legal form instead of the full one. Every difference is another round of document exchange.

What to do today: collect every item on that list in one folder, check the issue dates, and read the company name and address character by character on each document separately. An hour of work that saves weeks.

Amazon: your catalogue needs codes you may not have

Amazon identifies products by GTIN — its signed-in Seller Central help describes this as a 12–14-digit identifier such as a UPC, EAN, JAN or ISBN. Without one, in most categories the listing simply won’t be created.

That’s a real difference from the platforms you may already sell on. On Allegro a product identifier matters, but you can list without one. On Amazon the process stops.

Amazon documents a way out: a GTIN exemption, applied for in Seller Central — if a product has no GTIN, the seller may be eligible to request an exemption. The detailed requirements (documentation, photographs, category and brand conditions) live in the signed-in help pages and vary by category. Check them for the actual range before assuming the application will go through.

What to do today: count how many products in the catalogue have an EAN and how many don’t. That single number tells you whether you’re buying a block of codes from your national GS1 organisation or walking the exemption route for a private label. GTIN and EAN catalogue readiness is the part of the prep that pays off on every channel, not just Amazon.

eBay: configuration is per marketplace, not per account

The first item is small but recurring. eBay is explicit: if you sell as a business, supply your VAT number so you don’t pay VAT on fees. Without a VAT ID on eBay fees, the VAT on commission and platform fees lands on the seller. It doesn’t block selling — it quietly raises the cost base.

The second item is structural. Business policies — the shipping, payment and returns settings for each eBay site you want to sell on — are configured per market. eBay business policies per marketplace means policies from one eBay site won’t carry over to another. The reason is mundane: delivery options differ by country. Three markets, three sets of payment, shipping and returns policies.

Then there are new-seller selling limits: eBay may apply selling limits to new sellers until required information is confirmed. Limits apply per account, per category and per item. Category limits are applied when, among other conditions, fewer than 90 days have passed since the first sale, or the seller hasn’t sold many items in that category. Raising a limit requires contacting support and can depend on confirming account details and on seller performance metrics; category limits are reviewed on the account’s monthly seller-level evaluation cycle.

The practical consequence for a launch plan: the first three months on eBay are a ramp written into the platform’s rules, not a reflection of how fast your client can work. Say that out loud in the kickoff meeting rather than discovering it in month one.

What to do today: decide which eBay markets are in scope, prepare a shipping, payment and returns set for each, and get the VAT number onto the account.

OLX: the lowest barrier to entry, but choose the package deliberately

OLX has the simplest start. An account is created by email or via Google, Facebook or Apple, and the key step is switching a private profile to an OLX business profile. That unlocks the seller tooling: a company page on an OLX domain, OLX PRO for managing large listing volumes, CSV import (hundreds of listings from a template), listing promotion and top-listing paid visibility, plus consolidated invoicing and a spend limit.

The scale is real — OLX reports 17 million monthly active users. But the payment model looks nothing like Amazon’s or eBay’s. OLX packages aren’t one price ladder for everyone: pricing depends on industry, sub-category and listing count. OLX publishes a calculator on its business site where you pick those three parameters in sequence; the result is an indicative price, not an offer. Final rates are in the price list on olx.pl.

The consequence: a package chosen by gut feel before launch may not fit the actual number of listings, and changing it mid-stream means extra configuration and downtime.

And the thing that’s easiest to forget on OLX precisely because the platform reads as private classifieds: selling as a registered business carries the ordinary obligations — invoices or receipts under Polish law, the consumer right of withdrawal, complaints handling. Exactly as on any other channel.

What to do today: run the real listing count for the category through the OLX calculator and see which package makes sense at that scale.

Four things to do regardless of when the integration lands

1. Assemble the company documents. Every item on Amazon’s list, a statement no older than 180 days, and the company name and address written identically on every document.
2. Decide which eBay markets are in scope — and prepare a separate shipping, payment and returns policy set for each. Add the VAT number so you aren’t paying VAT on fees.
3. Count the listings and pick the OLX package in the calculator, rather than changing it a week after launch.
4. Audit the catalogue. How many products have an EAN and how many don’t. Whether names, identifiers and categories are in a shape that can move to any platform.

Point four is the most important and the most often skipped. An adapter moves data that exists — it won’t invent an EAN, split a product name out of its description, or fill in a missing category. A catalogue tidied today is what turns a finished integration into sales in days rather than weeks.

The prep is yours; the adapter is ours

Every item above is platform-independent prep work. Done once, it holds regardless of which adapter ships first, and regardless of whether the eventual sync layer is OpenLinker, something a client already pays for, or something an agency builds itself.

If the underlying reason for looking at Amazon, eBay or OLX is that too much of the revenue depends on one channel, that dependency can be reduced sooner. For a client selling into Poland, ERLI is a shorter path than any of these three — cheap to test and available now. And if a second channel already exists and it’s the operations that hurt — one stock pool, several admin panels, quantities drifting apart during the day — that’s worth fixing before the third channel rather than after. We wrote the mechanics up separately in how to sync orders and inventory across marketplaces, and if you’d rather look than read, there’s a live demo.

The preparation doesn’t have to wait for any adapter — and it’s the one part of this that’s entirely within your control. If you’re the one running this checklist for a client, see how agencies build a service around OpenLinker.