Acumatica Inventory Availability Explained: On Hand vs. Available

If you’ve ever looked at an item in Acumatica and asked “it shows stock on hand, so why can’t I pick it?” — you’ve run into the difference between On Hand and Available quantity. This guide breaks down exactly how Acumatica calculates inventory availability, how Available for Shipment is calculated specifically, and gives you a full glossary of every quantity column on the Inventory Summary (IN401000) screen.

What Is Inventory Availability in Acumatica and Why It Matters

Every stock item in Acumatica tracks two very different numbers: what’s physically sitting on the shelf, and what’s actually free to use. Confusing the two is one of the most common sources of warehouse errors — a picker sees stock “on hand” and assumes it’s free, when in reality it’s already been allocated to another order.

• On Hand is the physical quantity in the warehouse — what you’d count walking the shelves.
• Available is On Hand minus everything already committed elsewhere: open sales orders, allocated stock, unreleased issues, and more.

Getting this distinction right is the difference between a smooth picking process and daily “why is this short?” support tickets.

How Acumatica Calculates Available Quantity

The Core Formula

At the highest level, Acumatica calculates availability like this: Available = On Hand − Deductions + Additions The exact fields included in Deductions and Additions depend on the Availability Calculation Rule assigned to the item’s Item Class (configured on the Item Classes / IN201000 form). That’s why two items can show different Available quantities even with the same On Hand — their classes may be using different rules.

What Reduces Availability (Deductions)

These are the quantities that get subtracted from On Hand — and they’re almost always the answer when On Hand and Available don’t match:

• SO Booked — quantity tied to open sales orders that haven’t shipped yet.
• SO Allocated — quantity specifically reserved/picked for a sales order. This stock is spoken for and shouldn’t be picked for anything else.
• SO Prepared — quantity on sales orders still On Hold, Pending Approval, or Rejected.
• SO Back Ordered — quantity on backorder because there wasn’t enough stock to fill the order.
• IN Issues — quantity on an unreleased inventory issue document.

What Increases Availability (Additions)

These add back to the available pool, when the item class is configured to include them:

• IN Receipts — stock on an unreleased inventory receipt.
• PO Receipts — stock received against a Purchase Order but not yet released.
• Purchase Orders — stock ordered from a vendor but not yet arrived.
• In Transit — stock that’s left one warehouse via transfer but hasn’t arrived at the destination yet.

How Available for Shipment Is Calculated

Available for Shipment is a narrower, shipment-focused number — it’s the quantity you can actually put on a truck right now. Acumatica calculates it as: Available for Shipment = On Hand − Quantity Shipped − Quantity on Unconfirmed Shipments In plain terms: take what’s physically on hand, subtract anything that’s already shipped, and subtract anything currently sitting on a shipment that hasn’t been confirmed yet. Unlike the general Available quantity — which also factors in open sales orders, purchase orders, and transfers — Available for Shipment focuses specifically on what’s happening at the shipping dock: has it gone out the door, or is it in the process of going out the door? This is the number warehouse and fulfillment teams should check right before staging or loading an order, since it reflects shipping activity in real time rather than the full sales-order pipeline. A closely related figure, Available for Issue, uses a similar but separate calculation — On Hand minus shipped quantity — and applies to inventory issues rather than sales shipments.

Full Glossary of Inventory Summary Terms

Term	What It Means
On Hand	The physical quantity in the warehouse right now.
Available	On Hand minus everything already committed — the true “free to use” number.
Not Available	Quantity sitting in a location flagged as excluded from availability (e.g., a quarantine or damaged-goods bin).
Available for Shipment	On Hand minus shipped and unconfirmed-shipment quantities — what’s ready to ship right now.
Available for Issue	On Hand minus shipped quantity — the equivalent figure for inventory issues.
SO Booked	Quantity tied to open sales orders that haven’t shipped.
SO Allocated	Quantity specifically reserved/picked for a sales order.
SO Prepared	Quantity on sales orders still On Hold, Pending Approval, or Rejected.
SO Shipped	Quantity already shipped (confirmed) but possibly still finishing invoicing.
SO Back Ordered	Quantity on backorder because of insufficient stock.
IN Issues	Quantity on an unreleased inventory issue document.
IN Receipts	Quantity on an unreleased inventory receipt document.
PO Receipts	Quantity received against a Purchase Order but not yet released.
Purchase Orders	Quantity ordered from a vendor but not yet received.
In Transit	Quantity that’s left the source warehouse via transfer but hasn’t arrived at the destination yet.

Common Pitfall: Why On Hand and Available Don’t Match

The single most common support question around this topic is: “the system shows stock on hand, so why won’t it let me pick it for this order?” The answer is almost always SO Allocated or SO Booked — the stock is physically present, but it’s already promised to a different sales order. Before assuming there’s a data problem, check those two columns first.

Quick Checklist: Reading Inventory Availability Correctly

• Always check Available, not just On Hand, before promising stock to a customer.
• If Available seems too low, check SO Allocated and SO Booked first.
• Use Available for Shipment — not Available — when deciding what’s ready to load on a truck today.
• Remember that the calculation rule is set per Item Class, so different item classes can behave differently.
• Train more than one person on reading these columns — relying on a single team member to interpret availability creates a bottleneck and a single point of failure.

Frequently Asked Questions

What’s the difference between On Hand and Available in Acumatica? On Hand is the physical quantity in the warehouse. Available is that physical quantity minus everything already committed — open sales orders, allocations, and unreleased issues — representing what can actually be sold or picked. How is Available for Shipment calculated in Acumatica? Available for Shipment equals On Hand minus the quantity already shipped minus the quantity on unconfirmed shipments. It reflects what’s ready to physically leave the warehouse right now. Why does an item show stock On Hand but can’t be picked for a new order? This almost always means the stock is already allocated or booked to a different sales order (see the SO Allocated and SO Booked columns), even though it’s still physically present in the warehouse. Does every item use the same availability calculation? No. The specific fields included in the calculation are controlled by the Availability Calculation Rule assigned to the item’s Item Class, so different item classes can calculate availability differently.

Conclusion

Understanding the gap between On Hand and Available — and specifically what Available for Shipment measures — is one of the fastest ways to cut down on warehouse confusion and mis-picks. Once your team knows to check SO Allocated and SO Booked before assuming there’s a data problem, most “why can’t I pick this?” questions answer themselves. Is your warehouse team running into inventory availability confusion? ClandBus can walk your team through Acumatica’s inventory screens and set up training tailored to your actual workflows. Contact us or learn more about our specialized Acumatica support.   Acumatica: Availability Calculation Rules