Yes, if you wish to change / upgrade / add the product(s) / service(s) after activation, you can do so after paying the relevant difference amount.
You just need to drop an email to our billing team at support@truedata.in with your TrueData ID or registered mobile / email ID and specify the changes you need.
Our billing team will provide you with the amount required to be paid along with the payment link, after the payment is received, your account would be updated accordingly.