To determine the most useful QuickBooks function for Shariz to record the receipt of a vendor invoice, we need to analyze each option and match it with the task at hand.

Solution By Steps

Step 1: Identify the Task

The task is to record the receipt of a vendor invoice. This implies that an invoice has been received from a vendor and needs to be documented in QuickBooks.

Step 2: Analyze Each Option

New Invoice: This is typically used to create an invoice to send to a customer, not to record an invoice received from a vendor.

Add Bill: This function is used to enter bills that your business owes to vendors. It is the process of recording an invoice received from a vendor.

New Expense: This is used to record expenses, not specifically for recording vendor invoices.

Add Receipt: This is generally used to record receipts of payments made, not for recording vendor invoices.

Process Payment: This is used to make payments on bills, not to record the receipt of an invoice.

Step 3: Select the Appropriate Function

Based on the analysis, the function that directly relates to recording a vendor invoice is Add Bill.

Final Answer

The most useful QuickBooks function for Shariz to record the receipt of a vendor invoice is Add Bill.