July 28, 2026 · 6 min read

Automatic purchase orders in Shopify: reorder points explained

A reorder point turns restocking from a daily guessing game into a threshold: when stock on a product drops to a number, it's time to order more. Automating it means an app watches that number for every product and raises the purchase order for you — you approve and send, instead of remembering to check.

What "automatic" actually means here

No app should place an order with your supplier without you seeing it first — that's how you end up with stock you didn't mean to buy. What automatic PO generation actually does is remove the manual math and the manual draft:

• It tracks sales velocity per product, not a single store-wide number.
• It combines that with each product's supplier lead time to compute a reorder point (see the full formula in how to calculate a reorder point).
• When on-hand stock crosses that point, it drafts a purchase order pre-filled with a suggested quantity and the right supplier.
• You review the draft and send it — one click instead of a spreadsheet lookup.

Where lead time comes from — and how it self-corrects

Lead time is the weak link in most reorder-point setups, because merchants set it once and forget it. Supplier lead times drift — shipping gets slower, a new supplier has different terms — and a stale number quietly produces bad reorder points either way: too early wastes cash on excess stock, too late causes a stockout.

Reorda records the date a PO is marked as ordered and the date it's actually received. After a handful of orders with a given supplier, it compares the real average against the lead time on file and surfaces a one-line suggestion — "actually ~12 days — update?" — rather than silently drifting out of sync.

Setting it up

1. Attach a supplier and lead time to your products (bulk-assignable if you're moving fast — see assigning suppliers to hundreds of products at once).
2. Set a safety-stock buffer, either store-wide as a default or per product.
3. Let a few weeks of sales accumulate so the velocity number is meaningful.
4. Check the low-stock view — products approaching their reorder point show up there before they run out, with a suggested order quantity attached.

Who this is overkill for

If you carry a handful of SKUs and reorder once a season, the spreadsheet is fine — automating a decision you make four times a year isn't worth the setup. This earns its keep once you're checking stock levels weekly or more, across enough products that eyeballing them stops being reliable.