Sales order (SO)

Glossary / Sales order

How it works

A sales order sits between an estimate and an invoice. The estimate is an offer. The sales order says the customer has accepted and you are committed. The invoice bills what you actually delivered.

Sales orders matter most when stock is involved. They let you see which items are promised to customers, so you do not sell the same unit twice. When only part of an order can ship, you invoice what shipped and the rest stays open as a backorder.

Service businesses that bill straight from an estimate often skip sales orders. Wholesalers, distributors and shops taking special orders use them every day.

Worked example: A partly shipped order

A wholesaler takes an order for 100 cases of olive oil at $42 a case, $4,200 in all. Only 60 cases are in stock.

The wholesaler ships 60 cases and invoices $2,520 (60 × $42). Income and receivables go up by $2,520. The sales order still shows 40 cases, worth $1,680, as backordered. When the next delivery arrives, those 40 are shipped and invoiced, and the sales order closes.

In AcboBooks

In AcboBooks, a sales order posts nothing. Inventory on it shows as committed on the Stock Status report. You invoice it in part or in full from the sales orders list, a quantity per line, and the rest stays backordered. The Open Sales Orders by Item report lists every line still to ship with stock on hand.

Related terms

• Estimate
• Invoice
• Purchase order (PO)
• Inventory valuation
• Accounts receivable (A/R)

Related on this site

• Inventory in AcboBooks
• Invoicing in AcboBooks
• Templates

Updated October 25, 2026. General information, not tax, legal or accounting advice. Rules and rates change; check with the IRS, the CRA, your state or province, or your accountant.

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