Letter Asking a client to Submit more Documents

Dear Sir/Ma’am. I [title][name] am writing to you about your project [project name] assigned to [organisation name] on [date]. Currently your [project name] is in [design/development/testing] stage. Our {department name} is working tirelessly on it. However, they have arrived at a point where they require [document name] for moving ahead with the [project]. They have been through the [documents] delivered at the time of project assignment but they require more...