I'm only getting an error saying 'there is an invoice created with that number already." how do I get a different invoice number?

Thanks for laying out the details of your concern with us, @ecallender-dsmtt.

I'd be happy to walk you through the steps for getting a different invoice number in QuickBooks Online (QBO).

Follow these steps to proceed:

1. Go to the Sales menu, then select the All Sales or Invoices tab.
2. Select any invoice, then select Edit invoice. Or, select Create invoice to create a new invoice.
   
3. From the invoice window, click the small Gear icon in the upper-right corner.
4. Place a checkmark in the Custom transaction numbers box.
    
5. In the Invoice no. field, enter the custom number or letter sequence you want to use for your forms.
   
6. Once done, select Save or Save and close.

For more information about setting up a numbering preference for your sales form, refer to this article: Add custom transaction numbers to sales forms in QuickBooks Online.

In addition, you'll want to personalise the appearance by adding specific information to your sales forms. To know more about this process, you can check out this article: Customise invoices, estimates, and sales receipts in QuickBooks Online.

I'm all ears if you have any other concerns about invoice numbers in QBO. Simply leave the details in your reply and I'll take care of them for you. Keep safe and have a good one!