I just gave someone an estimate on a job and the total came out to be just under $5500 for the whole job. I agreed on payments. The customer gave me $2200, the cost of materials and then agreed to have the entire bill paid off within 4 months. How do you guys go about this? Do I write someothing up, have the customer sign it and then get it notorized? I have never had someone make payments so this is new to me. Thanks for the help.