Best App to Track Inventory & Create POs for Your Shopify Store

If you’ve ever checked your Shopify stock and then discovered your warehouse, Shopify, and Amazon all showed different numbers… you’re not alone.

Most merchants hit this stage at some point. It usually happens right after your catalog grows, sales pick up, or you start buying from multiple suppliers.

At that point, the simple tools that worked in the beginning start creating more confusion than clarity. Stockouts creep in, bundles stop syncing properly, and POs turn into a mix of spreadsheets and email threads.

That’s when an Inventory + PO app becomes a lifesaver by keeping your numbers accurate, your reorders on time, and your operations sane.

Let’s break down what a strong system should actually look like.

Why Shopify Merchants Need an Inventory + PO App

As your Shopify store grows, inventory stops being something you “track” and quickly becomes something you have to control.

More SKUs, more suppliers, more channels, and faster order volume create complexity that basic tools or spreadsheets can’t handle.

That’s where a dedicated Inventory + PO app becomes essential. It helps you stay ahead of stock issues, streamline purchasing, and keep your operations running smoothly without constant manual fixes.

Here’s why it matters:

• Inventory becomes harder to manage as SKUs increase
  Once you scale beyond a few dozen products, manual tracking becomes error-prone and slow.

• Stockouts happen without proper reorder planning
  Without automated triggers and reorder points, you usually realize something is out of stock after a customer tries to buy it.

• Bundles and multipacks don’t sync component stock
  Shopify doesn’t adjust inventory for bundle components accurately, leading to overselling and messy fixes.

• Multi-channel sales cause overselling without real-time sync
  Selling on Shopify, Amazon, Etsy, or anywhere else requires instant inventory updates, otherwise your numbers fall apart fast.

• POs are messy and slow when tracked manually
  Spreadsheets break, supplier emails get buried, and purchase orders get delayed.

• No clear view of what’s on order or when it arrives
  Without a centralized PO system, you’re always guessing delivery timelines and expected stock.

• Teams waste time fixing stock issues manually
  Hours go into verifying counts, editing orders, and correcting mistakes that shouldn’t happen in the first place.

Shopify’s Native Inventory & Purchase Order Limitations

Shopify handles basic inventory needs well, but its native tools aren’t built for growing merchants who manage multiple suppliers, bundle products, or sell across various channels. As operations scale, these limitations become clear.

Limited PO Functionality & No Integrations

Shopify’s PO system is minimal. You can create and receive a PO, but there are no approval workflows, cost automation, attachments or integrations with suppliers, accounting tools, or 3PLs. For any serious purchasing workflow, it quickly falls short.

No Forecasting, Velocity Tracking, or Reorder Logic

Shopify doesn’t calculate sales velocity, predict when items will run out, or recommend reorder quantities. This forces merchants to rely on manual checks or spreadsheets, increasing the risk of stockouts.

Weak Bundle & Component Handling

Shopify does not automatically sync bundle sales with component inventory. When a bundle sells, component stock often remains unchanged, leading to inaccurate counts and overselling—one of the most common issues for bundle-heavy stores.

Incomplete Multi-Location & Cross-Channel Sync

While Shopify supports multiple locations, it doesn’t manage inventory for external channels like Amazon, eBay, Etsy, or additional Shopify stores. Each channel updates separately, which leads to discrepancies and inventory drift as sales increase.

No Centralized Supplier Management

Supplier information, lead times, and cost history are not stored in Shopify. There’s no structured way to track supplier performance, compare cost changes, or manage purchasing data in one place.

Missing Automation & Inventory Intelligence

Shopify provides no low-stock alerts, automated replenishment, or inventory insights. Everything from monitoring stock to creating POs must be done manually, which becomes inefficient and error-prone as order volume grows.

What an Ideal Inventory + PO Workflow Should Look Like

A high-performing Inventory + PO workflow doesn’t just track stock, it gives your business control, predictability, and operational clarity.

The goal is simple: every movement of your inventory and every purchasing decision should be timely, accurate, and data-backed.

Here’s what that looks like when done right.

1. One Source of Truth for All Inventory

Inventory should update instantly across all channels and locations. Whether stock moves because of a Shopify order, an Amazon sale, or a warehouse transfer, the numbers stay accurate everywhere. This eliminates overselling and ensures teams rely on a single, trusted view.

2. Forecasting That Tells You What to Order and When

A modern workflow should replace guesswork with data. You should see which products are selling fastest, when they’ll run out, and exactly how much to reorder based on real demand. Timely alerts ensure you never discover a stockout after it’s too late.

3. Purchase Orders That Practically Build Themselves

Creating a PO should be a fast, structured process. The system should auto-fill supplier details, costs, and lead times, and support clear approval steps before the order goes out. This removes manual errors and makes purchasing consistent no matter who is handling it.

4. Collaboration That Stays Inside the System

Notes, attachments, receipts, and communication shouldn’t live in email threads or spreadsheets. When teams can comment directly on POs, upload files, and scan barcodes in one place, issues get resolved faster and data stays organized.

5. Complete Traceability Across Suppliers and Costs

Every supplier interaction past POs, delivery performance, cost changes should be visible historically. This level of traceability helps you plan future buys more accurately and negotiate based on actual performance data, not assumptions.

6. Integrations That Keep Operations Moving

Your workflow should connect seamlessly with 3PLs, accounting tools, and internal systems. Automated notifications for approvals, low stock, or delayed shipments keep teams informed without chasing updates manually.

Case Study: A Shopify Merchant’s Shift to Smarter Inventory & PO Workflows

A growing beauty brand on Shopify was managing over 300 SKUs, selling bundles, and fulfilling orders from multiple locations. With Amazon added as a second channel, the cracks in their workflow quickly showed up.

Challenges Before Switching

The issues weren’t random, they were directly tied to Shopify’s native limitations and their manual processes.

• Bundle inventory didn’t sync component stock correctly, causing frequent overselling
• Shopify and Amazon quantities drifted apart during high-volume days
• Purchase orders lived in spreadsheets with no visibility into what was ordered or already received
• Team spent hours reconciling stock weekly
• Reordering was reactive because they had no forecasting or low-stock alerts
• Supplier data, lead times, and cost changes weren’t tracked anywhere

This created constant decision-making delays, last-minute purchases, and inaccurate inventory across channels.

What Improved After Moving to a Dedicated Inventory + PO System

Once they implemented a proper workflow, the impact was immediate. Real-time syncing, automated replenishment signals, and structured PO management eliminated the guesswork.

Key improvements included:

• Real-time sync across Shopify, Amazon, and warehouse locations
• Accurate bundle/component deductions on every sale
• Forecasting that highlighted projected stockouts and recommended reorder quantities
• PO creation became faster with auto-filled supplier details, costs, and lead times
• Full visibility into incoming inventory and expected delivery dates
• Centralized supplier performance and cost history

Results Achieved in 90 Days

The operational shift was measurable and meaningful:

• Stock accuracy improved from 82% to 99%
• Overselling on Amazon dropped to nearly zero
• PO creation time reduced by 70%
• Reorder planning became proactive instead of last-minute
• Supplier delays decreased after tracking lead times and performance

Conclusion

As Shopify businesses grow, basic tools and spreadsheets can’t keep up with the pace of operations. Stock starts drifting, POs get messy, and teams spend more time fixing issues than moving forward.

A dedicated Inventory + PO system like Sumtracker removes this friction by giving you real-time accuracy, clearer purchasing workflows, and reliable forecasting, all in one place.

With Sumtracker, inventory becomes predictable instead of stressful. You reduce stockouts, avoid overselling, and make smarter buying decisions backed by data.

For any scaling merchant, this shift isn’t just helpful, it’s essential for running a stable, efficient, and growth-ready operation.

FAQs

1. Why isn’t Shopify’s native inventory system enough as my store grows?

Shopify covers basic tracking, but it lacks forecasting, supplier management, bundle syncing, and advanced PO workflows. These gaps become major bottlenecks once SKU count or order volume increases.

2. How does an Inventory + PO app like Sumtracker help prevent overselling?

It syncs stock in real time across all channels Shopify, Amazon, eBay, retail locations so inventory stays accurate everywhere and orders never exceed available stock.

3. Can a dedicated PO system improve my supplier communication?

Yes. It centralizes supplier details, tracks cost changes, stores past POs, and gives visibility into lead times, removing the need for scattered emails and spreadsheets.

4. Does an Inventory + PO app also track supplier history?

It should. Good systems store past POs, cost changes, lead times, and supplier performance to help you make better purchasing decisions.

5. Will switching to an Inventory + PO app reduce manual work for my team?

Significantly. Automated syncing, low-stock alerts, and quick PO creation eliminate manual checks and data entry, freeing your team from constant fixes and reconciliations.

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