Rebuilding simplified version of my account, how can I enter a one line income matching the deposits for the year?

Hello, David.

Yes, that's doable. QuickBooks uses the Sources and Targets concept when generating financial and business reports. This shows that each report's data was derived from the details of the transaction that served as its source.

Since the Profit and Loss report reveals the net profit and loss based on your revenues and expenditure. In this report, the deposit transaction won't be visible. This is the reason why it doesn't show any income account.

If you don't have one, let's create an income account and a service item. After that, create a Sales receipts to offset the negative amount of the Undeposited Funds account. This will also be your income transaction for the P & L report. I'll show the step-by-step process.

Step 1: Create an Income account.

1. Go to the Lists menu, then Chart of Accounts.
2. Select New in the Account dropdown.
3. In the Add New Account window, choose Income, then Continue.
4. Enter your desired income account name in the Account Name field.
5. Once done, hit Save & Close.

Step 2: Create a Service item.

1. Go to the Lists menu.
2. Select Item List.
3. Click the Item dropdown, then choose New.
4. Select the Service from the Type dropdown.
5. Enter your desired name 
6. In the Account dropdown, choose the Income account you create above.
7. Fill in all the necessary information.
8. Once done, hit OK.

Step 3: Create a Sales receipts.

1. Go to the Customers menu.
2. Select Enter Sales Receipts.
3. You can leave the Customer Job field blank.
4. Enter the date in the Date section.
5. In the Item column, choose the service item you've created.
6. Enter a positive amount to offset the negative figure in the Undeposited Funds.
7. Once done, hit Save & Close.

After that, you can record a bank deposit to transfer the fund from Undeposited Funds into your bank account.

Let me know if you have further questions or concerns. We're available to help you at any time.