[These are sample Letter format for Converting of Mobile Plan. You can follow these sample as an application for converting postpaid to prepaid or prepaid to postpaid plan etc. you can modify these sample as your requirement.]
The Manager Operations, (Job Designation)
Telecom Company name…
Sub: Application for Converting Postpaid to Prepaid
I wish to apply for the change in my mobile plan from postpaid to prepaid, being a regular customer of your company since year (Date). I have to take this step on account of the exceeded amount of bill which I have paid for last three months (More/less) and all this happened because I don’t have a check on my mobile plan. (Describe your own cause and situation).
Anyhow, I am not facing any kind of issues with respect to the services provided by your company. It is, therefore, requested that my mobile plan may please be changed into prepaid so that I could manage my monthly budget easily. (Describe your requirements).
If you require any further information, please contact me at my mobile number.