Ive lost all my invoicing data

Allow me to share some steps you can take to retrieve your lost invoice data in QuickBooks Online (QBO), Martin.

First off, please ensure that you're using the correct account. When you have multiple accounts associated with one set of login credentials, you must select the specific account you wish to access. However, if you are using the correct account and the invoice is missing, we can check the Audit Log report/history to review if the invoice was deleted. 

Here's how:

1. Click on the Gear icon in the upper right corner and select Audit Log.
2. Use the Filter button to narrow down your search.
3. Choose the filters you would like to use and click on Apply. 

Furthermore, if there are no records of the deleted invoices, let's try accessing your account through a private browser to determine if it's a browser-related issue. If the invoices are visible in the private browsing window, we can proceed with clearing your cache to resolve the issue. If the issue persists, you may need to consider using another supported browser.

Additionally, you can check out this article to learn how to personalize your invoices: Customize invoices, estimates, and sales receipts in QuickBooks Online

Please let me know if you need additional help with invoices in QuickBooks Online. I'll be around to provide further assistance. Keep safe.