Most stockouts aren't a surprise — they're a slow leak that nobody happened to notice in time. Someone would have to open the inventory sheet, scan the stock count column, and manually compare every single number against some threshold they're keeping in their head. Skip that check for one busy week, and a bestseller is suddenly sitting at zero.

In this tutorial, we'll build a Low Stock Alert — a Product table that automatically flags any item as "Low Stock" the moment its count drops below a set threshold. No scanning, no mental math, no restocking surprises.

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Table Columns

Here's what we're working with — a Product table with Name, Stock Count, and Reorder Threshold.

Product table columns showing Name, Stock Count, and Reorder Threshold fields

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Step 1: Add Your Products

Add a handful of products with different stock levels and thresholds, so we can see the flag behave once it's built.

Product table populated with sample products including a mug, a notebook, and a pair of headphones

For this walkthrough, assume we have:

• Ceramic Mug — Stock Count 42, Reorder Threshold 10
• Kraft Notebook — Stock Count 8, Reorder Threshold 10
• Wireless Headphones — Stock Count 25, Reorder Threshold 15

Right now, nothing here tells you at a glance which of these actually needs reordering — you'd have to compare each pair of numbers yourself, one product at a time.

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Step 2: Flag Products as Low Stock

Since a plain column can't be converted into Custom Logic after the fact, create a brand new column and set its type to Custom Logic from the start.

Adding a new Custom Logic column for the Low Stock flag

Describe the rule — if Stock Count falls below Reorder Threshold, mark it "Low Stock"; otherwise mark it "In Stock."

Describing the logic to flag products where Stock Count falls below Reorder Threshold

Confirm the clarification screen, checking that it's comparing Stock Count against each product's own Reorder Threshold, not a single fixed number.

Clarification screen confirming the comparison uses each product's individual Reorder Threshold

Save it, and every row resolves instantly:

• Ceramic Mug → In Stock
• Kraft Notebook → Low Stock
• Wireless Headphones → In Stock

Product table showing Low Stock flag filled in only for the Kraft Notebook

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Step 3: Watch a Sale Trigger the Alert

Let's prove that live. Suppose 12 Wireless Headphones sell in one afternoon. Update its Stock Count from 25 down to 13.

Updating Wireless Headphones Stock Count from 25 to 13 after a sale

The moment it's saved, the flag updates on its own.

Wireless Headphones changes from In Stock → Low Stock, the instant the count crosses its threshold of 15.

Wireless Headphones now showing Low Stock after its Stock Count dropped below the threshold

Now suppose a restock shipment arrives for the Kraft Notebook, bringing its count from 8 up to 30.

Updating Kraft Notebook Stock Count from 8 to 30 after a restock

Kraft Notebook changes from Low Stock → In Stock, immediately.

Kraft Notebook now showing In Stock after being restocked above its threshold

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Step 4: Build a Restock View

Create a new view, filter where Low Stock equals "Low Stock," and save it as "Needs Reorder."

Saved filtered view named Needs Reorder showing only products flagged as Low Stock

Now whoever handles purchasing doesn't need to scroll through the full catalog — only the products that actually need attention show up here.

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Recap

1. A Product table with Stock Count and a per-product Reorder Threshold
2. A Custom Logic field flagging products as Low Stock, kept current through triggers
3. A live demonstration of the flag reacting to both a sale and a restock
4. A filtered view surfacing only the products that need reordering

This same threshold-flagging pattern extends well beyond inventory — low account balances, minimum staffing levels, or usage limits on a subscription plan can all be tracked the same way, just by describing what the threshold means in that context.