The Expense Accounts, WIP Accounts, and Invoicing Accounts tabs allow you to define costing accounts for the job. The defaults for these accounts are set up in Module Preferences, but if you want to use different accounts for a job, you can override the defaults on these tabs.

If you change the accounts directly on a Cost Code in the job, it will override the accounts in Module Preferences and these tabs.

You can quickly access these tabs from the Job menu on the left navigation pane.