Hi there, Valeria Kennelly.
Thanks so much for bringing your question forward here in the Community. I'd be glad to provide some info about linking estimates to projects in QuickBooks Online.
You can add existing estimates to projects as long as they haven't been converted to invoices yet. There are a couple of ways to get this done. Here's how:
1. Hover over the Sales tab, then click All Sales.
2. Choose the money bar showing Estimates.
3. Click to open the estimate without the project name that you'd like to add.
4. Edit and change the customer name to the one containing the project name also.
5. Select Save when you're finished.
Another option is to:
1. Navigate to Sales from the left menu and select Customers.
2. Find the customer and click the name to open.
3. Locate and open the estimate.
4. Click the drop-down arrow on the customer field. Look for the name of the project and select it.
5. Choose Save.
I have a couple of articles for you that provide additional info about this process. You can check them out here:
That will do it. With this info, you'll be able to link existing transactions to newly created projects. Please feel free to reach back out if you have any other questions.