First, you need to activate the setting on your Leave Categories page:

1. Log into your Payroll classic platform.
2. Click on Payroll Settings.
3. Click on the Leave Categories option.
4. Select the required leave category. 
5. Select the Prevent Negative Leave Balances tick box. Please note this option will only show if you select the Tracked option to the Employee Leave Balance question.
6. When you select the Prevent Negative Leave Balances setting, a drop-down menu appears. It contains the leave categories that are set to Do Not Pay for the Leave Taken and have the same unit type as the selected leave category.
7. Click the Save button.

Leave without pay will automatically apply to the part that exceeds the available leave balance at the time the pay run is processed. The linked unpaid leave category cannot be deleted when you link it to another leave category.

When you open the pay run and there are leave requests that fall within the pay period, the leave requests tab displays at the top of the page, listing details of each request. In this view you can see:

• Employee name.
• Type of leave requested: Leave category associated with the leave request.
• Dates of leave requested: By default, the dates will align with the pay period dates where a leave request spans multiple pay runs.
• Unit type for leave requested:  Unit type associated with the leave category
• Number of units requested: The units requested will align with the leave request, even where the leave request spans multiple pay runs.
• Units to apply to pay run: The units to apply to the pay run align with the first and last dates entered. You can edit this value up to the units requested value or where partial units have already been applied in another pay run, the balance of units left to allocate.
• Units paid within pay run:  We calculate this value based on the units applied to pay run. If you have the Prevent Negative Leave Balances setting enabled, paid units will not exceed the available leave balance. We will allocate values that are more then the available leave balance to units unpaid. If you disable this setting, we will allocate the full amount as paid units.
• Units unpaid within pay run: We calculate this value based on the units applied to the pay run. If you have the Prevent Negative Leave Balances setting enabled, we will calculate the unpaid units balance of the units applied that exceed the available leave balance. If you disable the setting, there will not be an unpaid section.

Having the negative leave balance setting enabled, will affect how units paid and unpaid display. Employees taking leave for a leave category which prevents a negative leave balance may have unpaid units. Whereas if they are taking leave for a leave category which does not prevent negatives, they will only have paid units and could have a negative balance that must be earned back.