I am trying to add expenses and do invoicing but my app does not have gst as an option all of a sudden it is on the desktop but not the app

Hi longhornweldingi,

Thanks for reaching out to us here.  I can understand the concern, when QuickBooks Online isn't offering sales tax, while creating your invoices.  This has been reported by other users, so you're not alone.  Our Development Team is currently investigating the issue, and have advised that customers make sure all line items have a tax code, when using the mobile app to create estimates and invoices.  If you experience the same outcome, please don't hesitate to contact our Customer Care team at 1-855-253-1536 from Monday to Friday between the hours of 9 AM and 8 PM EST. They will be able to add you to the list of affected users, and set you up to receive an email notification when it's been fixed.

If you have any other questions, feel free to reach out again.  We would be glad to help!