So my invoice numbers randomly changed. Does anyone know how to find out what the last invoice number were and how to change the invoice numbers back?

Hello, natasha_v.

Another user may have edited the invoice numbers or it's likely caused by the automatic numbering sequence. I'll show some solutions to help you find out what the last invoice number was and change it. 

For the sequence, QuickBooks automatically increments the invoice number by one on both custom and standard transaction numbers. This explains why the invoice numbers changed. 

We can open the affected invoices, then change the numbers back. To determine what the last invoice number was, I'll include the details below. 

Next, we can check to see if a user edited the invoice number. Let's do this by checking the Audit log report. This is where we can also see what the last number was before it was edited. Here's how to pull it up: 

1. Go to the Gear icon menu, then select Audit log. 
2. On the filter parameters, set a specific user under User and the date under Date changed.
3. Under Events, select All transactions. 

We'll want to look for Edited Invoice description, then click on View to see what the last number was. Open the invoice then change the number. 

For more details about custom transaction numbers and the Audit log, we can check out these articles: 

• Add custom transaction numbers to sales forms in QuickBooks Online
• Use the audit log in QuickBooks Online

If you need help recording invoice payments in full or partial, I'll share this article: Record invoice payments in QuickBooks Online. 

You're more than welcome to drop by here if you have questions about your invoices. If you need help with expenses, reports or any other thing in QuickBooks, let me know and I'll help you out.