Hi Mandy,

Let me show you how to deal with this in QuickBooks.

It is safe to create an invoice as it is the only way to clear the unbilled activities. Make sure that the invoice total will be zero. 

1. Go to Sales.
2. Click All Sales. 
3. Click on Filter drop-down button. 
4. Select Unbilled income on Type.
5. Click Apply.
6. Select the transaction you would like to create an invoice.
7. Click on Batch actions drop-down button and click Create invoices.

There is a feature to  batch remove unused billable expenses, but it may not work for those brought in from Desktop

https://community.intuit.com/questions/1366993-how-do-i-delete-old-unbilled-expenses-and-time-charge...

After all those invoices are made, what then? Now I have 1.5 million in invoices? 

Thanks for joining this conversation, @Funkeinc.

As long as the invoices that were created have a zero total amount, you don't need to worry about them. This will also clear your unbilled activities in QuickBooks Online (QBO).

You may also check out the article shared by my colleague above for future reference.

For tips and other resources, I recommend visiting our website for reference: Self-help articles.

Reach out to me in the comment section below if you have any additional concerns. I'll be happy to help. Have a good one!