TriNet Expense allows you to "lock in" approvers for your users on the Manage Users page (only Company Owner and Admin have access to Manage Users page.)
1. Go to Settings > Company Settings > Manage Users
2. Click yellow lock icon next to approver field:
- Locked = will prevent the user from changing their approver from their Report Settings page.
- Unlocked = user's will have the approver you've setup as their default approver, but have the ability to change the approver email.
Note: this setting is optional, but it is recommended to lock approvers to avoid user interference with report approval.