CORE allows you to automatically approve time and expense entries, if required. In such cases, employees do not need to submit their entries for approval. Under Global Settings > Time & Expenses, there are rules that allow you to auto approve expense entries for projects and employees. If you have 'Auto approve expense entries for projects' checked, CORE ensures that expense entries get automatically approved for all new projects. For existing projects, you have to enable the rule 'Auto approve expense entries' from the Projects > General > Assignment > Rules screen.
If 'Auto approve expense entries for employees' is checked, expense entries logged by all new employees are automatically approved. If you want this to apply to existing employees, you need to check the 'Auto approve expense' option from the Employees > General > Rates & Options screen. Check CORE Help Center for details on Global Settings.
Note: The Auto Approve options set from the Global Settings screen aren't applicable to existing projects or employees; they are applied to newly created projects or employees. Similarly, if you disable the auto-approve rules, it does not affect the existing entries, but only to the new entries.