Which of the following must be included on a sales invoice?

The inclusion of specific details on a sales invoice is critical for legal compliance and effective record-keeping. The correct answer encompasses a comprehensive set of information required on a valid sales invoice. These details include:

• Invoice number: This unique identifier helps both the seller and the buyer to reference the specific transaction.

• Seller’s name and address: Essential for identifying who is issuing the invoice and their location, which is important for both tax purposes and legal accountability.

• VAT number: If applicable, this identifies the seller in the VAT system, ensuring compliance with tax regulations.

• Invoice date: This indicates when the sale occurred, which is crucial for record-keeping and accounting timelines.

• Customer details: Including the customer's name and, often, their address, which can be necessary for shipping and for the buyer’s record-keeping.

The inclusion of these elements not only aligns with best practices in invoicing but also meets legal requirements in many jurisdictions to ensure transparency and clarity in business transactions. Other options do not provide the comprehensive information necessary for valid sales documentation, leading to potential issues in compliance and record accuracy.