When a tenant is due to pay his late fee, the late fee is displayed on the payments page in a separate column. 

If the tenant does not pay the late fee, enter the late fee as 0. The fee is carried over to his lease period, as a balance amount. 

But if the invoice amount is paid in advance, the balance amount is adjusted with the late fee in the total invoice amount. 

How to create late fee on your 6Storage account