Is it possible to undo a delete of an invoice?

Hi there, @gisearthworks-gm. I'd be happy to help you recover the deleted invoice in QuickBooks Online (QBO).

In QBO, the option to undo the deletion of an invoice is unavailable. You'll have to recreate it. To do so, let's use the Audit log report to take note of the details of the deleted transaction. I'll guide you on how:

1. Navigate to the Settings menu and select Audit Log.
2. Then, in the Filter dropdown menu, select the appropriate user, date, and event(s).
3. Next, click Apply.
4. From there, locate the deleted transaction. 
5. Under the History column, select View.
6. You'll find all the information needed for the transaction under the Event column.
7. Use that information to re-enter the invoice with its original transaction date.

For reference, check out this article: Use the audit log to re-enter deleted transactions.

Once everything is fine, your next step is to record payments for your customer invoice. 

Keep me posted if you have any other concerns about managing invoices in QBO. I'm just around the corner to lend a hand. Have a good one and stay safe.