Why is it? I'm matching sales and as an example, I have a transaction for customer A for $77.40 - open match screen and the transaction is not there.

Welcome to the Community, Nerina. I'd be happy to clarify how QuickBooks matches your e-transfer transactions.

In QuickBooks Online (QBO), when you attempt to match a bank transaction to a sale, QBO searches for transactions that align based on the amount, date, and details such as customer names, payees, and descriptions. However, the way payments are recorded in QBO can influence how they appear during the matching process.

When you matched the $200 transaction, QuickBooks likely considered the $77.40 as part of that amount, treating it as a partial payment or combined deposit. This is why some transactions may not appear separately when matching, as QuickBooks processes e-transfers differently depending on how they were recorded.

To match transactions correctly in QBO, first verify your Sales or Customer records to ensure the $77.40 transaction is associated with the correct customer and payment method. Suppose multiple payments are combined into a single lump-sum deposit ($200 shown in your bank feed), you can use the Bank Deposit feature to accurately group and match these payments.

Refer to this guide for more information on matching transactions in QBO. 

Feel free to leave a Reply in this thread if you have any further questions or concerns. I'm only a post away. Have a great day!