You need to set the correct declaration date in your payroll module first, followed by setting the correct tax parameters in the income tax module. Please follow the steps below to do this:
Declare Date
Go to the Payroll module, Pay Records, and select the period and year.
Double-click the employees, then double-click the Bonus pay element.
Ensure the Declare Date is set as the tax year declaration.
Tax parameters
Go to the Income Tax module, then click Process.
Click Income Tax and click Proceed From Step 1.
Click Edit and enable the option To include Following Years Pay element Declared in Current Year Until Period (eg. you may choose 1 if you are paying the bonus in January).
Click Next to continue.
