Addition in iec

Hi, I have a proprietorship company and have an e-IEC for that concern. This concern has a main office and a branch office and both of these are mentioned on the e-IEC certificate. This concern is about 7 years old. Now i have just started another proprietorship concern which has the same address as the above concern and this concern will also be involved in import and export. How do i add this new concern in the existing e-IEC? I tried to do it online but it only gives me an option of adding another branch address. It doesnt give me the option of adding another concerns name. Kindly help me with the procedure to add this new concern as i need to start importing and exporting asap. Await your prompt reply. Thank you. Rgds, Kapil T