How can IGST apply automatically on product which i purchase from other state vendor

Let me provide some insight on applying IGST on the product automatically, @mehul9k.

When you create expenses or bills for your purchases from other states, you'll want to make sure that you selected the correct IGST tax rate. This way, it'll be reported to the receiving vendor.

However, I still recommend contacting our Phone Support Team to make sure you'll have an accurate reporting in QuickBooks Online (QBO). They can also provide additional information about how IGST works in QBO.

To reach them, you can click the ? Help button at the top-right corner and select Contact Us to talk with a live agent.

You might want to check out this article to learn how to apply IGST on invoices: How do I apply IGST on my invoices?

Keep in touch if you need any more assistance with this, or there's something else I can do for you. I've got your back. Have a good day.