Rent to Own Rent Credits

[Brian Lubeck]

I own a park that came with a handful of park owned homes and I have been renovating them and putting them on the market as rent to own.  I am having success at executing the rent credit model. I am charging lot rent along with regular rent.  The portion of regular rent goes towards their rental credits every month.   My question to other owners is, do you charge interest and have that clause spelled out in your documents?   

I currently do not have that clause in my documents and my accountant brought it to my attention.  I would really appreciate some feedback from you all as to how your documents are structured for this.  Thank you in advance!