Pre approvals are a one-off request to be able to claim expenses under a certain time period/project. The limit(s) for expense types under pre approvals may be different to the employee's usual expense limit(s).
For example, John has an upcoming business trip to attend. The cost of the trip exceeds the expense limit of $200 for transport claims. John can submit a pre approval to allow him to make an expense claim that exceeds this limit.
Pre approvals can also be requested by a manager for their team member(s) or by an admin.
Similar to expense claims, pre approvals:
Are bound by the expense types that the employee is entitled to
Have to be approved by someone within the company
Thus, the expense admin should ensure that expense types are set up properly and that the relevant expense types have been assigned to employees.