My logo has disapeared and when I upload it again it still does not show on my invoices

Thanks for reaching out to the Community forum, grahammoore1.

I'm here to provide information to make sure that you'd able to add logo into your QuickBooks Online account.

Before adding a logo, make sure that the following logo requirements were met:

• The logo is a .gif, .bmp, .png, .jpg, .jpe, or .jpeg file.
• File size is smaller than 10 MB.
• Have a bit depth (or colour depth) of 24-bits or less.
• Uses the standard RGB colour space (RGB).
• The shape of the logo is square. Rectangles don't work.

Once verified, I recommend accessing your account in a Private browsing window first to verify if this is caused by the system or your browser.

Here are the keyboard shortcuts that will help you accomplish this in all supported browsers:

• Google Chrome: press Ctrl + Shift + N
• Mozilla Firefox: press Ctrl + Shift + P
• Internet Explorer: press Ctrl + Shift + P
• Safari: press Command + Shift +N

Once able to open a private browser, try to add logo again. If it works, then your main browser may have too much historical data from previously visited websites which slows down internal processes and causes this kind of behavior.

To ensure this doesn't happen again, it's a good idea to clear the cache of the browser you're using.

For additional information in a adding a logo, here's a great resource that you can check: How to add, customise, and troubleshoot logo on sales forms.

If there's anything else I can do for you when uploading a logo, let me know by commenting below. I'd be happy to further assist you. Have a great day.