Guide to setup ecommerce business


This is more of an accounting query, than about the software.
I have tried reading through the guides, and have figured some parts of setting up the business out.
But there are certain specific queries mentioned below that i would like to have figured out:

I sell my products on multiple e-commerce portals for eg. Amazon and Flipkart.
When i sell/ship a product to a customer, i create a sales invoice. For eg. The value of that product is Rs. 100 (incl. of tax)
When i get paid in my bank for the same, it happens after deduction of all the charges/marketplace fees (seller channel comission {eg. Rs. 20} + courier/delivery charges {eg. Rs. 10}) - so basically i get paid Rs. 70 (100-20-10) in my bank account.
I want to understand how to setup accounts for the same - so that i can track what has been paid to each marketplace for their respective fees.
Basically i want to track/record fees paid to amazon and flipkart separately. Also if possible i want to track market place fees paid to amazon and courier/delivery fees paid to amazon separately as well.
For this do i need to create new accounts, if so how do i do it? What is the correct way to do it?

Separately, I want to know if I have sold inventory to a customer and want to record freight expense on it (to be borne by me), is using purchase invoice the correct way to record this expense?

Kindly refer me to the correct guides which would solve my query.
I would like to apologise in advance, if this query is very specific and doesn’t fall in the ambit of the forum discussions.

Specific answers to your questions depend on exactly how you get your information on charges from the e-commerce portals. Also, if you are selling through these portals, you may not need to use sales invoices. Sales invoices are for selling on credit to defined customers. You aren’t doing that. The portal is making the sale, deducting some expenses, and passing the balance on to you. That all has to be understood better.

As for how to create accounts, see this guide:

You would use a purchase invoice or payment, allocated to a shipping expense account. If you are not charging the freight to the customer, it is just another cost of doing business.