Thanks for the prompt responses.

Another idea is to use alerts with internet banking that can serve as great prompts and reminders.

We tend to have very long term tenants because we take care of repairs promptly and keep the rents slightly below market value. 

Thanks so much for all the great responses and promptness!

Completely agreed - I just wanted to see the excel so I could understand how things are calculated, then I'll be fine with the software after a couple of them :) And great point about the brokers and getting out and networking - a meeting I had with a broker is what prompted me to get a model I could really understand!

Thanks for the prompt reply.  

Thanks everyone for your prompt responses.

@Essam Elkady thanks for your prompt  response.

You never know the level of motivation, nor the criteria, prompting their decisions.

I have waived the late fee since she paid promptly today (1 day late).