Hello Mark, I hope you can help me. I was just wondering if the Invisalign treatments have to be paid in a just one lump sum or if it can be paid monthly or something like that? I live up North, so I would be using the practice that would be closest to me. I have an over-bite and my top teeth are almost straight though my bottom set are in need of sorting, therefore if there is somewhere I can pay it monthly I will definitely book mine as soon as I know. Thank you in advance for your advice.