An estimate is a non-binding price projection. A quote is a fixed-price offer that becomes a contract when accepted. A sales order is the buyer's formal commitment to purchase. The flow: estimate (optional) → quote → buyer's purchase order or sales order → invoice. This guide explains each document, when to send which, and how they flow together in B2B sales.
Usually no — for small to mid-size B2B, an accepted quote serves as both. Sales orders become useful when dealing with enterprise buyers.
Same agreement, different perspective. The buyer issues a PO; the seller's matching internal document is the SO.
Yes — when the buyer accepts the quote (signature, written reply, or deposit payment), the quote IS the agreement.
Invoice against the most recent agreed document. Reference the SO/PO number on the invoice if one exists.
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