What is a sales invoice?
Published
A sales invoice is the document a business issues to its customer claiming payment for goods delivered or services performed. When the supply is taxable - the default - it is itself the tax invoice, with all its requirements; the two names are the commercial and statutory faces of one document.
What it creates the moment it issues
Al-Waha's SAR 34,500 invoice creates three numbers in three places at once:
Receivable 34,500 ← an asset on the balance sheet (owed to you)Revenue 30,000 ← in the income statementOutput VAT 4,500 ← a liability to ZATCA
Plus the fourth entry that accompanies goods: cost of sales / inventory. Issuance is the moment of revenue recognition - not collection, and not handover to the courier.
Its lifecycle
Draft ← no accounting effectIssued ← revenue, receivable, and VAT arise (Phase 2: after clearance, for standard invoices)Sent & tracked ← collection and remindersPartial/full payment ← receipt vouchers close the receivable downCorrection if needed ← a credit or debit note; never edit, never delete
Common mistakes
| Mistake | Effect |
|---|---|
| Batching issuance to month-end | Revenue and tax land late, and collection slows - every day's delay in sending is a day's delay in getting paid |
| Treating collection as the revenue event | Double-counting or gaps: revenue arose with the invoice; collection only closes the receivable |
| Invoicing before supply "to lock the customer in" | Revenue and tax before they are due; the right tools are a quotation or a properly treated advance |
| Deleting a wrong invoice | Prohibited; correction is a linked note |
Frequently asked questions
What is the difference between a sales invoice and a supplier bill?
The same document from two sides: your invoice to a buyer is your "sales invoice" and their "supplier bill." For you it creates revenue and a receivable; for them, an expense/asset and a payable.
When do I invoice a long-running service?
Per the contract: milestone billing or periodic billing - with revenue recognition still following delivery, not billing alone.
A customer asks for a "preliminary invoice"?
They usually mean a quotation or proforma - documents with no accounting or tax effect. A real tax invoice is not used for that purpose.