Thanks for taking the time to share your concern here in the Community, useranwar_p. 

I'm here to share some insights with you about adding a GST number. As of now, we're unable to add multiple GST numbers in QuickBooks Online. As a workaround, you'll have to create a separate QuickBooks account for each tax id.

I appreciate your idea about this feature. I'll take note of this. In the meantime, I recommend visiting our QuickBooks blog from time to time to get the latest news and product improvements.

For more information about handling GST in QuickBooks, I suggest checking this article: Setting up QuickBooks for GST.

Additionally, I've included an article that'll help you learn more about how GST impacts QuickBooks users: GST FAQs.

Please reach out to us if you have other concerns or queries related to GST. This way, we'll be able to help you out.