Good day! I want to ensure that you'll be able to connect to HMRC, @lauraburne.
Before we proceed, can you share with me the error message you're seeing when connecting to HMRC? This would help me in verifying the cause of the issue and provide you an appropriate solution to this concern.
If the Test User credentials are correct and you're still unable to connect with HMRC, this might be a browser-related issue. Sometimes stored cache in a browser can cause unexpected behavior with the product. To fix this, we can run some basic troubleshooting steps.
Let's start by accessing your account in a private window. Doing this won't save your search records and browsing history from your browser. Simply press the following keys:
Google Chrome: Ctrl + Shift + N
Mozilla Firefox: Ctrl + Shift + P
Safari: Command + Shift + N
If it works, you can go back to your regular browser and clear its cache. A piled cache can also be the reason for the unexpected issues on the pages we've opened like QuickBooks.
You also have the option to use a different browser like Google Chrome, Mozilla Firefox, or Safari. There are times that the browser we're currently using has page maintenance.