How do I edit my invoice to have my ABN on it?

You can customise your invoice template, bigdogautopd-gma.

Note that this will only affect invoices created moving forward. Follow the steps below:

1. Click the Gear icon.
2. Select Custom form styles.
3. Click Edit on the invoice format.
4. Select Content.
5. Click the header, then check the box for ABN.
6. Enter your ABN.
7. Click Done to save changes.

That's it! Your Australian Business Number will now appear on your invoices. You can also customise other sales forms in QuickBooks: Customise invoices, quotes, and sales receipts in QuickBooks Online.

Let me know if you need anything else, I'll be more than willing to help.