How can I disable automatic generation of invoice numbers?

It’s great to see you today, pseltsam.

Thanks for joining the QuickBooks Community. You'll have to customize the invoice template so you can manually enter the invoice number.

I’ll walk you through the process:

1. On the Invoice page, click the on the Formatting tab located in the upper left.
   
2. To tailor it, click on the Customize Data Layout icon.
   
3. On the Additional Customization page, go to the Header tab.
   
4. In the Invoice Number section, unmark the boxes for Screen and Print. This will remove the invoice number field.
5. Click on OK.
   

Once done, the default Invoice # field will no longer show on the transaction. However, in the right-hand corner, you’ll see the INVOICE NUMBER field.

You can use that box to manually enter the transaction number. Please know that even if you’ll disable the Invoice # field, QuickBooks will sequentially assign the number for reporting purposes.

For future reference, check out the Use and customize form templates article.

That should do the trick. Let me know about your success following these steps. I’ll be right here if you need further assistance.

If you tab to the Number field on invoice, you don't have to delete the existing number first.  Just start typing your 'manual' number and the pre-filled one will disappear.  When you tab to that number field (as opposed to placing your cursor in it), the entire number should be highlighted in green, which indicates when you start typing the other number disappears.  If you are using the mouse and the cursor is placed at the beginning of the number field, then you can type your new number but will have to delete the old one.

I found this answer.   I tried it.  This almost works, but I need to see the invoice box on the screen to be able to put in the invoice number.    We already do change the invoice number every time.    This should be an option given in preferences just like the option for check numbering.

It's great that you gave these steps a shot. I hear what you're saying about them not quite working for you and encourage you to submit feedback to the product development team by going to the Help menu and choosing Send Feedback Online. We love hearing from customers about ways that we can enhance what the product is doing to meet their business needs. In the meantime, please continue to use the method you have been using of changing the invoice number each time. Let me know if you have more questions!