Which transaction does not affect the customer's balance?

An estimate does not affect the customer's balance because it is a proposal for future work rather than an actual sale. When you create an estimate in QuickBooks Online, you are providing a potential pricing and service overview to the customer without recording any financial transactions. Since an estimate is not an official transaction, it does not impact the accounts receivable or the customer's balance until it is converted into an invoice or sales receipt.

In contrast, invoices and sales receipts represent actual sales, which do directly affect customer balances. Payments reduce a customer's outstanding balance, thereby impacting their liability. Thus, while invoices, payments, and sales receipts create changes in the customer's financial status, an estimate solely serves as an account of potential future sales without altering the existing balance.