I cannot include an expense anymore. QB says there is an error on the tax payment but I’ve tried all possible solutions.

Hello mmalmeida1,

Welcome to Community!  QuickBooks Online, is currently experiencing a validation error when trying to create expenses from receipts.  This is being investigated by our Development Team.  Although I don't have an ETA for resolution, you can 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 set you up to receive an email notification when it's been fixed.

Please feel free to reach back out with any other questions. We would be happy to help!