Shopify inventory forecasting for stores not using Shopify POS

The problem with Shopify-only forecasting

Most Shopify inventory apps calculate demand velocity by looking at your Shopify order history. That works perfectly if Shopify captures 100% of your sales. But most merchants selling physical products don't operate that way.

You might sell at weekend markets. You might have a retail location running on Square or Lightspeed. You might do wholesale orders that come in by email. None of that shows up in Shopify.

This means you'll consistently underorder and run out of stock faster than your forecasts predict. Or you'll manually adjust every recommendation, which defeats the purpose of having a forecasting tool at all.

Why merchants don't use Shopify POS for everything

Shopify POS works well for some merchants, but it's not the right fit for every situation:

• You're already locked into a POS system with staff trained on it (Square, Clover, Lightspeed, Toast)
• Your wholesale or B2B orders come in through email or a separate portal
• You sell at markets or pop-ups using a simpler mobile setup
• You have a retail partner or consignment arrangement
• Shopify POS fees don't make sense for your transaction volume

Switching POS systems is expensive, disruptive, and often not worth it just to get better inventory data into Shopify. The better solution is to import your offline sales data directly into your forecasting tool.

How to get accurate forecasts with offline sales data

The approach that works without switching your POS:

1. Export sales data from your offline system

Most POS systems (Square, Lightspeed, Clover, etc.) let you export a CSV of transactions. You want a file with at minimum: a product identifier (SKU or name), a date, and units sold. Many systems also include current inventory levels, which is useful.

2. Map your SKUs to Shopify products

For blended forecasting to work, your offline product identifiers need to match your Shopify SKUs. If you use the same SKUs in both systems, you're ready. If not, you may need to do a one-time mapping exercise.

3. Import and blend

Stockwise lets you upload your offline sales CSV, map the columns (SKU, date, units sold, units on hand), and it automatically blends that data with your Shopify order history. Matched SKUs get a combined velocity calculation. Unmatched SKUs appear as offline-only products with their own forecasts.

4. Re-import regularly

Set a recurring reminder, weekly or monthly, to export from your POS and import into Stockwise. Once your column mapping is saved, re-imports take under a minute.

What a blended forecast looks like

Say you sell a product that moves 5 units/week on Shopify and 3 units/week at your market booth. A Shopify-only forecast would calculate 5 units/week. A blended forecast would calculate 8 units/week, which changes your days-of-stock calculation and your reorder recommendation significantly.

Which merchants benefit most

• Boutique retailers with an online store and one or more physical locations
• Artisan and maker brands selling at markets, fairs, and craft shows
• Wholesale brands with B2B accounts outside Shopify
• Brands with retail partnerships or consignment arrangements
• Any merchant where Shopify represents less than 80% of total sales