Is there a way to assign a journal to a project?

Yes, there's a way to add a journal entry to a project in QuickBooks to track wages by job for costing purposes, Rachael93.

1. Go to Reports tab, then enter Journal in the search bar and click the Journal report.
2. Select the date range from the Report period. 
3. Filter section, Select Transaction Type, and equals then choose Journal Entry from the drop-down.
4. Click the Journal Entry you created.
5. In line with the expense account, enter the project name in the Name field.
6. Click Save or Save and new.

Once done, you can check your Project if the journal entry is already under the Transaction tab.

Here's how:
 

1. Go to Projects.
2. Click the name of the project.
3. Select the Transaction tab.

To learn more about this, you can refer to this article: Create and manage projects in QuickBooks Online and Accountant.

Additionally, you can check this article to learn how to manage your journal entry: Reverse or delete a journal entry in QuickBooks Online.

Please click the Reply button if you have any other questions regarding managing projects or adding journal entries in QuickBooks . I'm more than happy to help.