Spreadsheets work until they suddenly don't — usually right around the point a stockout or a costly overorder makes the cost of poor visibility painfully obvious. Here's how to choose the right software for your stage.
Signs you've outgrown spreadsheets
Common warning signs include: reconciling stock counts across multiple sales channels manually and finding regular discrepancies; spending more than an hour a week on inventory-related admin that feels like it should be automatic; experiencing stockouts on products you 'thought' had stock because a spreadsheet wasn't updated in time; or managing more than roughly 100–200 SKUs across more than one warehouse or sales channel. Any one of these is a reasonable signal to invest in dedicated software rather than continuing to patch spreadsheet workflows.
Entry-level inventory management systems (IMS)
Tools like Cin7 Core (formerly DEAR), Katana, and Ordoro sit between basic platform-native stock tracking and full ERP complexity — they typically offer multi-channel stock sync (so your Shopify, Amazon and eBay listings all reflect one accurate stock count), purchase order management, and basic manufacturing/kitting support for private label sellers assembling bundles or simple products. Pricing commonly runs £200–£600/month depending on order volume and channel count, a reasonable investment once manual reconciliation is costing more time (and stockout/overorder risk) than that.
Full ERP systems
NetSuite, SAP Business One, and Microsoft Dynamics 365 Business Central are full enterprise resource planning systems, integrating inventory with accounting, procurement, HR and often manufacturing into a single system of record. These make sense once a business has grown complex enough that disconnected best-of-breed tools (separate accounting, inventory and CRM systems) create more reconciliation overhead than a unified system's higher cost and implementation complexity — typically once a retailer is processing high order volumes across multiple warehouses, currencies or business units, or has outgrown a mid-market IMS's reporting and workflow capabilities.
ERP implementations are a serious undertaking — commonly 3–9 months and significant consulting cost for a mid-sized retailer — and should be approached as a business transformation project, not simply a software purchase, with dedicated internal ownership rather than treated as an IT-only initiative.
What to evaluate before choosing
- Native or well-supported integrations with your actual sales channels and platform (Shopify, Amazon, eBay, your accounting software) — a system requiring custom integration work for basic channel sync adds significant hidden cost.
- Real-time (not batch/delayed) stock sync across channels, to avoid overselling out-of-stock items.
- Multi-warehouse and multi-location support if you use more than one storage location or a 3PL, including the ability to route orders intelligently between them.
- Reporting depth — can you actually get the ABC analysis, forecast accuracy, and margin-by-SKU reports you need, or only generic stock-level views.
- Ease of use for whoever will operate it daily — the most feature-rich system is worthless if your warehouse or operations staff find it unusable.
Migration and implementation tips
Whichever system you choose, run a parallel period (operating both the old and new system simultaneously for at least a few weeks) before fully cutting over, to catch data migration errors and workflow gaps before they affect live orders. Clean your product data (accurate SKUs, weights, dimensions, supplier lead times) before migration rather than after — garbage data migrated into a new system just becomes garbage data in a shinier interface, and cleaning it retroactively is considerably more painful than doing it once, properly, at migration time.
How This Connects to the Rest of Your Operation
Getting inventory management software and ERP systems: a UK retailer's buying guide right is rarely a one-off task — it tends to need revisiting as the rest of the business changes around it. Our companion guide, Warehouse Management Systems (WMS): A Buyer's Guide for Growing UK Retailers, goes into this in more depth.
Visibility is the other recurring theme. Whether you're managing your own stock or working with a third party, the retailers who scale smoothly are usually the ones who can see accurate, near-real-time data on where every unit sits — rather than reconciling spreadsheets after the fact. Investing in that visibility earlier than feels necessary tends to pay for itself the first time a supplier or carrier issue would otherwise have gone unnoticed for days.
Seasonality is one of the biggest variables UK online sellers underestimate here. Peak periods around Black Friday and the run-up to Christmas can see order volumes multiply several times over in a matter of weeks, and any weakness in your inventory, warehousing or fulfilment setup tends to surface exactly when it's most expensive to fix. Stress-testing your current approach against a 3x demand spike is a useful exercise even outside of peak planning season.
Cost isn't the only variable worth tracking. Delivery experience, damage rates and how quickly problems get resolved all feed directly into repeat purchase rates and review scores, so it's worth weighing operational choices here against their effect on the customer experience, not just against the invoice from your supplier or carrier.
For related reading: If you haven't already, PIM Explained: Do UK Online Retailers Need Product Information Management Software? is a useful companion read on this exact point. It's worth reading this alongside Marketplace Channel Management Software: Keeping Amazon, eBay and Your Own Store in Sync before making a final decision. For a closer look at this, see our guide to Inventory KPIs Every UK Online Retailer Should Be Tracking.