How do I add a subcategory? So if I want to label something as a 'Job Expense' or 'Job Expense-XYZ'.

Let me show you the easy steps on how to add a sub-category, wholewatersoluti. 

We'll have to add it first like dding a new account in our Chart of Accounts. From there, we can its parent account to be the sub-account (category). Let's make sure that they have the same account and detail type. 

Here's how: 

1. Go to the Accounting menu and select Chart of Accounts. 
2. At the upper-right, click New. 
3. Select the correct Account and Detail Type. 
4. In the Name field, we can enter something like Job Expense or if you prefer Job Expense-XYZ. 
5. Check the Is sub-account box and select the parent account from the drop-down. 
6. Enter the rest of the details and click Save and Close. 

When we look into the parent account, the sub-category is indented to show that its a sub-account. I have attached a screenshot on how it looks like. 

We can read through this article on how the parent and sub-account works. 

Reach out to me if you need anything else. Thanks!