Hi there, @rlopezmora. When you're company settings is correct, I'd suggest making sure that you set up taxes properly. The invoices that don't have tax won't have the ABN appear. Follow these steps below to fix:Select GST on the left-hand menu.Select Edit GST.Select Edit Settings.Update ABN details here.Click Save. I've added articles as your references:Change your business name, contact info, or ABN in QuickBooks OnlineChange company name, address, email address, ABN, and privacy settings In case your ABN isn't showing on your invoices, you can edit the invoice template you frequently use to make this appear. Tag my name below if you have any questions. I'll do everything I can to answer them.