paying the wrong amount of salary to an employee

SUGGESTED

Hi,

I have noticed that one of the employee has been paid less amount of her monthly salary for last 4 mounts. I am going to pay Dec salary, I am wondering how to pay this amount, because the employee standard salary is 850.20 and we paid around 613.12. 

Considering her standard salary she is not eligible to pay EE NI but eligible for ER NI. if I add the total amount of correction to this mount she get eligible for EE NI.

Please, help with this issue.