Build Basics: Square Data Model

Orders and Inventory Tracking

To understand how itemization and money movement is linked in the Square data model, you will need to understand the concept of an order.

Inventory API
Orders API

This topic walks you through the Square API concepts of an order and how order items are specified with a product catalog.

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Square uses orders to logically group items, discounts, and taxes so they can be linked to 1 or more payment. The item variations, taxes, and discounts included in an order can be pulled from an existing product catalog or defined ad hoc (at the time of the API call). For example, assume someone in California hears the podcast ad for Raphael's Puppy-Care Emporium and places an order online for:

  • 1 medium leather collar, engraved with a name.

  • 1 blue sweater, sized for a medium dog with 2-ply, with the podcast discount.

The final order includes 2 line items (with modifiers) and 3 price adjustments. The state sales tax and year-end sale discount are order-level price adjustments because they affect the price of everything in the order. But the podcast discount is a line-item price adjustment because it only applies to the handmade sweater.


When the customer pays for their order, the payment object references the order object to link it to the payment. Linking a payment and an order establishes the relationship between a monetary exchange and an itemized bill of sale (an order). And since orders are always associated with a specific location, Square can use the itemized details to automatically track the physical inventory of the item variations at that location (when the product catalog has inventory tracking enabled). Itemized payments and refunds can also be searched, updated, and managed using the Orders API.

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Orders can also be pushed directly into the Square POS for fulfillment management. For example, suppose a customer has installed an order ahead coffee app that allows them to order drinks and pay for them in advance.

Fulfillment orders are made with a nested object that tracks order status and other information required to fulfill the order. Once the order is charged, it is pushed to the Square Point of Sale app. Sellers can then use the Point of Sale app to manage fulfillment.

The Orders API currently supports Pickup and Shipment type fulfillments.

Inventory tracking
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Inventory is modeled as having a quantity of item variations in a given inventory status at a specific location. Inventory management is essentially the process of moving quantities of item variations between the different item states. For example, when the online order for a leather collar and heavy sweater is processed, the on-hand quantities for "Leather collar" and "Heavy sweater" are automatically updated by moving the number of purchased units for each item variation from IN_STOCK to SOLD.


In addition to automatic inventory tracking, Square also support nuanced inventory tracking (e.g., receiving stock, marking waste) and reconciliation.

Did you know?

Product catalogs and inventory tracking are not required to process payments with Square. But using these elements will improve reporting and make it easier to manage payments.