The advert that appears between the customer and billing addresses in invoicing about taking credit cards is very annoying how do I switch it off?

I'm here to provide steps so you can close the advert in QuickBooks, @sales211.

Those in-product pop-ups are designed to guide you to enhance your QuickBooks Online experience. For now, the only way to get rid of the advert is to click the X or No thanks button. Then, let the QBO save cache on the browser so this won't appear again. 

To learn more about the latest product updates in QuickBooks Online, please visit our QuickBooks Blog. This page provides details for product recent improvements, news, and product enhancements. 

You can always get back here if you have other concerns or questions about accessing your Quickbooks Online. I'll be here to help you. Stay safe.