Why does ecommerce inventory management matter for bookkeeping?

Because stock is an asset on your balance sheet, not just a warehouse problem. When physical stock counts drift from what your system says you hold, your cost of goods sold and gross margin numbers drift with it. Inventory errors don't stay in the warehouse, they show up directly in your financials.

What does a tool like Katana MRP actually do?

It tracks stock levels, production or purchase orders and sales in real time across every channel you sell on, so what your system says you have on hand matches what's actually on the shelf. For businesses that manufacture or assemble products, it also tracks the raw materials and components that go into finished stock.

Do I need dedicated inventory software if I'm already using Xero?

Xero's own inventory tracking is fine for simple, low-volume stock. Once you're selling across multiple channels, holding raw materials as well as finished goods, or managing more than a handful of SKUs, a dedicated inventory or MRP tool that syncs with Xero generally does a better job than trying to force Xero to do a job it wasn't built for.

How much stock discrepancy is normal?

Some variance is normal, breakages, miscounts, minor shrinkage. What's worth investigating is a consistent, growing gap between recorded and physical stock, that usually points to a process problem, not bad luck, and it's compounding cost you're not seeing until a stocktake forces the issue.

Ecommerce Inventory Management: What Actually Goes Wrong

Published August 2026By True Tally Bookkeeping7 min read

Why Inventory Errors Show Up in Your Books, Not Just Your Warehouse

Stock is an asset on your balance sheet. When the quantity your system says you hold drifts from what's physically on the shelf, your cost of goods sold calculation drifts with it, and so does your gross margin. A business can look profitable on paper while quietly bleeding stock nobody's accounting for, and the gap only becomes visible at stocktake, often months after it started.

This is why inventory isn't purely an operations problem. Get it wrong and the numbers your bookkeeper is working from are wrong too, no matter how carefully the rest of the books are kept.

Where Stock Tracking Usually Breaks Down

For ecommerce businesses specifically, the most common failure point is selling across multiple channels, a website, a marketplace, maybe a physical stall or wholesale account, without one system that sees all of it at once. A sale on one channel doesn't automatically decrement stock everywhere else, so two channels can both show the same last unit as available, and one customer ends up disappointed.

The second common failure is manufacturing or assembly. If you're combining raw materials or components into finished products, tracking finished-goods stock alone misses the picture entirely, you also need visibility over what's tied up in unfinished inventory.

Failure point	What it causes
Multi-channel selling, one stock count	Overselling, cancelled orders, refund costs
Manual stock updates	Drift between system and physical count
No raw material tracking	Blind spots in true cost of goods sold

A Dedicated Tool Worth a Look

Katana MRP is built specifically for this, real-time stock visibility across sales channels, plus manufacturing and raw-material tracking for businesses that assemble or produce what they sell. It's the kind of tool that earns its keep the moment your stocktake stops matching your system, since by then the gap has usually been growing quietly for a while.

Disclosure: The Katana MRP link above is a referral link. If you sign up through it, we may earn a commission at no extra cost to you. We only mention tools here that we'd genuinely point a client toward.

What to Check Before Your Next Stocktake

Do all your sales channels update the same stock count, or does each one track separately?
Are raw materials or components tracked, if you assemble or manufacture what you sell?
How much does your recorded stock typically differ from your physical count, and is that gap growing?
Does your inventory system sync with Xero, so cost of goods sold reflects reality, not a guess?

True Tally: bookkeeping that matches your actual stock

We work with Melbourne ecommerce and product businesses to make sure cost of goods sold reflects what's actually happening on the shelf, not what the system assumes. Book a free call.

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