All the filed vat returns for 2020 for a client appear to have disappeared. Have they been moved?

Hello, kevin32. 

No! Let's isolate this case by accessing your QuickBooks using a private window to verify if this is related to your browser issue.  

There are times that the browser stores frequently-accessed data, thus causing some errors or unusual behavior.    

Here are the different keyboard shortcuts to open a private browser:    

• Google Chrome: press Ctrl + Shift + N 
• Mozilla Firefox: press Ctrl + Shift + P
• Safari: press Command + Shift + N 
• Microsoft Edge: press Ctrl + Shift + P    

If using a private window works fine, you can go back to your regular browser and clear its cache. I'm including an article that goes over this in more depth and provides steps for supported browsers: Delete or disable cache and temporary internet files in your web browser.  

If the same thing happens, I recommend reaching out to our customer support team. One of our representatives will able to pull up your account in a secure session and help you review your account.    

Please note that customer service is available from M-F 6 AM to 6 PM PT and Saturday 6 AM to 3 PM PT. 

If there's anything else you need help with QuickBooks Online, please let me know in the comments below. I'd be glad to answer them. Stay safe!