Amazon Sellers Are Moving to Walmart: How to Sync One POS Inventory Across Both

If you sell on Amazon, you’ve probably noticed the conversation shifting lately. Sellers who once brushed off Walmart Marketplace as “too small to bother with” are suddenly paying close attention. And honestly, it makes sense once you look at the numbers. This is exactly why more sellers now want to sell on Walmart and Amazon inventory sync set up the right way from day one.

Walmart has now crossed 200,000 active third-party sellers. That’s not a rounding error anymore. It’s a real, credible second marketplace sitting right behind Amazon.

There’s another reason for the buzz. Walmart quietly trimmed referral fees across several categories, including apparel, electronics, and home goods. Pair that with zero monthly subscription costs, and you’ve got a platform that finally looks worth the effort.

The Catch Nobody Mentions

But here’s the part nobody talks about enough. The moment you add a second sales channel, you also add a second inventory headache. Suddenly you’re balancing stock counts in two places, and if they don’t talk to each other, chaos follows fast.

This guide walks through why sellers are making the jump to Walmart, and more importantly, how to keep one inventory system in sync across both platforms without losing your mind.

What Is Amazon and Walmart Inventory Sync?

Inventory sync connects your central inventory system with multiple sales channels. Your POS or inventory platform becomes the main source for stock information.

When inventory changes, the connected channels receive the updated quantity. This can include Amazon, Walmart, your website, and other marketplaces.

Walmart provides inventory APIs that allow sellers and approved solution providers to retrieve and update SKU quantities.

A proper setup can help synchronize:

• Product information
• SKU numbers
• Available inventory
• Orders
• Order status
• Shipment information
• Stock adjustments

The exact capabilities depend on your POS, inventory platform, and integration setup.

Why Everyone’s Suddenly Talking About Walmart

Let’s be real for a second. Amazon fees have gradually increased again this year. Fulfillment costs went up, inbound charges for bulky items got steeper, and sellers running tight margins are feeling the squeeze.

Meanwhile, Walmart has been investing heavily behind the scenes. Warehouse capacity for Walmart Fulfillment Services has grown a lot. There’s also a newer two-day shipping badge that’s closing the gap with Amazon Prime, which used to feel untouchable.

Less Noise, More Visibility

Then there’s competition, or the lack of it. Amazon has millions of sellers fighting for the same eyeballs on every listing. Walmart’s seller pool is growing fast, sure, but it’s still nowhere near as crowded, which means your products actually have a shot at visibility.

None of this means you should drop Amazon and run to Walmart. It just means a lot of sellers are treating Walmart as a smart second stream of income instead of ignoring it.

The Problem Nobody Warns You About

Here’s what usually happens. A seller gets excited, lists their products on Walmart, and things go well for a week or two. Then an order comes in on Amazon, and nobody updates the Walmart listing.

Now you’ve got a customer on Walmart buying something you don’t actually have. That’s not a small mistake. That’s a cancelled order, a frustrated buyer, and a dent in your seller rating.

Why Spreadsheets Won’t Cut It Anymore

The root issue is simple. Every extra marketplace you add creates one more place your stock count needs to live. If those numbers aren’t talking to each other in real time, you’re basically running two separate businesses on guesswork.

Spreadsheets might’ve worked when you had ten orders a week. They fall apart fast once you’re juggling real order volume across two channels. What you actually need is one central system that updates everywhere automatically.

How to Actually Set This Up (Step by Step)

Step 1: Pick a POS or inventory tool built for multichannel selling

Don’t just grab whatever’s popular. Look specifically for tools with a track record of connecting to both Amazon and Walmart. Lightspeed, Square, and Zoho Inventory are the names you’ll hear most often from sellers already doing this.

Each one has its own strengths, so think about your setup. If you also run a physical store, that changes which platform makes more sense for you.

Step 2: Connect your Amazon Seller Central account

This part is usually straightforward. Most POS platforms have a built-in Amazon connector or an app you can install directly.

You’ll need your Seller Central login and the right API permissions turned on. Once that’s done, your POS can start pulling orders and pushing stock updates without you lifting a finger.

Step 3: Connect your Walmart Marketplace account

Walmart works a little differently. You’ll usually go through the Walmart Marketplace API or a certified partner app inside your POS system.

Take your time here and map your Walmart catalog carefully to your existing SKUs. This is exactly where things tend to go sideways, so don’t rush it.

Step 4: Keep your SKUs identical everywhere

This sounds boring, but it matters more than almost anything else on this list. Use the exact same SKU for the same product on both Amazon and Walmart whenever you can.

If your POS lets you alias variants under one master product, use that feature. Messy SKUs are the number one reason multichannel sync breaks down.

Step 5: Build in a small stock buffer

Here’s a trick a lot of experienced sellers swear by. Set aside a small buffer between what you actually have in stock and what shows as available online.

This gives you breathing room if there’s ever a short delay in syncing. It’s a small habit that saves you from some very awkward customer emails.

Step 6: Test everything before going all in

Don’t connect your entire catalog on day one and hope for the best. Pick one or two low-stakes products and run a real test first.

Place a test order, or manually adjust the stock, and watch what happens on both platforms. If something’s off, you want to catch it now, not after a hundred products are live.

Step 7: Automate your order and shipping updates too

Once inventory sync is working, don’t stop there. Extend that same automation to order status and tracking numbers.

This way, the moment something ships, both marketplaces update instantly. Customers get accurate delivery info without you typing anything twice.

Step 8: Check in on your sync regularly

Even the best systems hiccup occasionally. Make it a habit to glance at your sync logs once a week, just to catch anything odd early.

A quick check now beats an ugly overselling surprise later.

A Few Mistakes Worth Avoiding

A lot of sellers treat this whole setup as a “set it and forget it” job. It’s not. Catalogs change, new products get added, and small SKU mismatches sneak in over time if nobody’s watching.

Fulfillment timelines are another sneaky trap. Amazon FBA and Walmart Fulfillment Services don’t run on the same schedule. If your sync setup ignores that, you risk promising delivery dates you simply can’t hit.

And don’t sleep on your buffer settings either. Too low, and you’ll oversell during a busy weekend. Too high, and you’re quietly turning away sales that could’ve been yours.

Tired of Juggling Spreadsheets Between Amazon and Walmart?

You didn’t get into ecommerce to spend your evenings manually updating stock counts across platforms. SKUPlugs connects your Amazon, Walmart, and POS systems into one real-time inventory dashboard, so your numbers actually match everywhere.

No more overselling. No more guessing games between channels.

See how SKUPlugs can simplify your multichannel setup and get back to actually running your business. Start with a 15-day free trial with no credit card required. You can also get setup assistance without a setup fee.