How do I add one-time earnings or variable pay components for my employees every month?

You can add one-time earnings or variable pay components to your employees while processing your monthly pay runs.

Go to the Pay Runs tab.
Click Create Pay Run or View Details if you already have a draft pay run.
Click next to the employee name and click +New Earning from the side panel.
Choose the incentive/ bonus/ commission from the drop down and enter an amount. You have to configure the component through Settings > Salary Components for it to show up here.
Click Save.

The one-time earning / variable pay component will be added to the employee’s pay for that pay period.

Alternately, you can import one-time earnings for a bunch of employees by uploading a XLS or CSV file.

Click Import/Export > One-time Earnings and Deductions.
Upload your CSV or XLS file containing the one-time earning details. You can view a sample file to make sure that you’ve entered the data in the correct format.
Select the Character Encoding and File Delimiter.
Click Next.
Map the Zoho Payroll fields with the columns in your import file.
Click Next.
View the import preview and click the Import button.

The earning will be added to the pay run once you click Apply Changes.