Is Quickbooks Down error 504?

QuickBooks is working fine, @nelsonetcom2005. Let's get rid of the error so you can get back to business.

Before we proceed, may I know how did you get the error? What task you're trying to do? Any additional information would be greatly appreciated.

In the meantime, let's perform some troubleshooting steps to get this fix. It's possible that the browser you're using had a data issue, thus causing QuickBooks Self-Employed (QBSE) to get unusual errors. To verify, let's log in to your QuickBooks Self-Employed (QBSE) account via a private browser. To do so, press this shortcut key on your keyboard:

• Google Chrome: Ctrl + Shift + N
• Mozilla Firefox: Ctrl + Shift + P
• Safari: Command + Option + P

If this works, it means that you need to clear the browser's cache so the system can start fresh. If you get the same result while using a private browser, I recommend switching to a different one. 

Please let me know how it goes by dropping us a reply below, @nelsonetcom2005. I want to make sure this issue is taken care of.

Just in case you want to learn how to track sales tax in QBSE, you can read through this article for more information: Learn how sales tax works in QuickBooks Self-Employed.

Have a great day and take care always.