According to the constitution, Every entity which is involved in selling/reselling of physical or virtual goods/materials, which results into generating income for the seller/Association, needs to get TIN.
Any e-commerce business which wants to accept online payments, needs to be a registered company. So as to be able to integrate an authorized payment gateway on the website.
You can register your ecommerce business under sole proprietorship at your nearest local municipal corporation office. You need to submit the Shops and Establishment Form to complete your registration. Along with it, you are needed to submit an undertaking.
You don’t need a separate PAN for your business for taxation purposes. Your personal PAN will serve the purpose. And when filing Income Tax returns, you will have to file returns in your personal name.
Service tax is applicable only if you’re selling a service to your customers. And similarly if you are selling goods, VAT, Excise and/or Sales Tax are applicable. But all these taxes come into play once you’ve crossed an annual turnover of 10 lacs. You may also need to consider Professional Tax, if you’re employing people.
The following link provides some good insight into the Shops and Establishments Act in Karnataka.
When do I need to apply for a Shops and Establishments Registration for my business in Karnataka?