How do I update an invoice that is linked to a quote? I have changed some numbers on the quote how do I link them?

Hi there, @contact34.

You'll need to delete the first invoice that is linked to the quote that you've updated and create a new one. Let me show you how.

In your QuickBooks Online (QBO) account:

1. Open the Invoice.
2. Hover to the 1 linked transactions link and click Remove. 
3. Once done, click More at the bottom of the invoice and click Delete.
4. Then, open the quote you've updated and click Create invoice.

I'm also adding this helpful article that can help guide you to learn how to customise invoice in QBO: Customise your Invoices, Quotes and Sales Receipts in QuickBooks Online.

As always, if you need further assistant, don't hesitate to leave a comment below. I'm always here to help.