When you enter a transaction directly into the register in QuickBooks Online, only one account can be associated with it.

However, you can then modify the transaction through the register window if you need to list multiple accounts on that particular transaction.

If the transaction has not been entered, it is always best to open the appropriate entry screen (Invoice, Bill, etc.) and associate split (multiple) accounts with the transaction when entering it.

To record multiple accounts for a transaction through the register:

  1. From the left menu, select Accounting, and select Chart of Accounts.
  2. Locate the appropriate account for the transaction.
  3. From the Action column, select View Register.The entry screen for that particular transaction opens.
  4. Enter the other accounts to add to the transaction and their respective amounts.
    Note: Make sure that the amounts for each account add up to the total amount of the transaction.
  5. Select Save..

The transaction now displays the correct total in the register, and Split in the account column.