One of my end clients has their own timesheet/invoicing portals. Can my worker use their online portal rather than Oncore's?

Oncore can facilitate the use of an end client online timesheet system.

Yes, an external timesheet system can be used, during the submission of a new contractor the timesheet system would be selected as external/paperbased. When the contractor submits a timesheet through a system that's external to Oncore's, they or the Recruitment Agency would need to send a copy (screenshot; print to PDF; photo) of the approved timesheet to supportaus@oncoreservices.com to be entered into the system.