How do I upgrade my Amazon Seller account from Individual to Pro ?

This is done on Amazon Seller Central following these steps: 

1

Locate and click on the Settings button on the top right-hand corner of the main Seller Central page

2

Click on Account Info 

3

Locate the section on the left-hand side that says Your Services click on Manage 

4

In the section that says Sell on Amazon locate where it says "Click to upgrade to learn the benefits of becoming a Professional" under the market place you wish to sell in with a Pro account ( for example Amazon.com) 

5

Complete the interview process online following the steps providing all the necessary information for your application to be approved.