When you enter a transaction in a register, you can “split” the transaction to different accounts, customers, jobs, or classes, so that you can keep track of how much you're spending on each account, customer, job, or class. From the register, you can also view split transactions that you entered by using the Expenses tab in the Write Checks, Enter Bills, Enter Credit Card Charges, or Create Item Receipts windows.
Restriction: From a register, you cannot view or enter a split transaction that tracks items.
If you don't know the total, leave the Amount field blank. QuickBooks totals the amount as you fill in the splits and displays it in the Payment field.
QuickBooks subtracts the amount entered from the total amount and displays the remainder on the next free line of the Splits window. If you left the transaction amount blank, QuickBooks adds the split amount to the transaction amount.
The class field appears only when you select the “Use Class Tracking” checkbox (choose QuickBooks > Preferences and click Transactions).
If the split amounts don't add up: As you enter amounts in the Splits window, QuickBooks enters the remainder on the next free line. Sometimes the total of the amounts entered in the Splits window doesn't equal the figure you originally entered in the register. This happens when you delete a splits line or change the total amount in the register. To balance your transaction, click the Recalc button in the Splits window.