Hi todd-brennan,
The best approach would be to grant your employees access to WorkZone which you can click here to see the steps of setting them up. If they already have access through this employee portal there is the ability to add in work expenses themselves for employer approval within the WorkZone app. By clicking here you can see a step by step guide of creating Expense Requests which include a Add Attachment feature to the request, such as an image of the receipt. This would be a good way to allow your employee's to remain separate from the overall payroll system and allow them to request expenses, hours work or even leave to the employer for approval in their next pay run.
-Steven
