Let me provide some information about adding a GST number in QuickBooks Online (QBO), india.accounts.
The option to add multiple GST numbers is unavailable in QBO. The only workaround is to open a separate QuickBooks account for each Tax ID. However, if you need to change the GST number on the invoice, just edit the transaction.
You can also configure a new tax for the new GST number. In the sales form, you can use the same on the Invoice. For reports, you cannot get GST reports, however, we can get inward and outward report as they used to be available for VAT/Service Tax. If you need to update your GSTIN/GST identification number, just go to the Taxes menu. Then, edit the GSTIN showing in your invoices. Here's how to do it:
Additionally, here are some articles that you can read to help personalize your invoice template and manage your GST-related transactions:
Feel free to update us after performing the steps in the comment below. I'd like to ensure this is resolved for you. Take care always.