Should I allow my tenant to pay 15th to 15th

[James Myers]

Has anyone ever had their tenant pay from the 15th to 15th based on their pay check cycle? 

I have a tenant that said the realtor I use to find tenants for me told him that he could pay on the 15th on each month.  I just found this out and thought they were paying late because they have had some banking issues that I have worked with them on.  But recently I have sent them notification that since the banking issue was fixed they would need to start paying before the fifth or be penalized. 

Even with the banking issue they have always paid between the 15 and 20th.  Should I allow them to have a due date of that or be a jerk and tell them the 5th and if after a late fee is added?

If I go with the 15th should I have a new contract signed adjusting the due date?