Hello there, @vinit2vinaya.
You may check the ABN (Australian Business Number) field using the Custom form styles feature in the QuickBooks Settings. Here's how to enable this field:
- Go to the Settings and select Custom form styles.
- Click on the New style button and choose Invoice.
- Select the Content tab and click on the header section of the sample preview to see the details in it.
- In the Header section, check the box with ABN.
- Select Done. This is how it looks like:
I've added this article to help you in the future to customise your sales forms such as quotes or sales receipts: Customise invoices, quotes, and sales receipts in QuickBooks Online.
Please don't hesitate to tag my name in the comment section below if you have other concerns or questions. I'm here to assist you further. Take care.