How do I enter subcontractor costs as a sole trader

As a sole trader, I often employ other people to complete part of my work and than charge that on to my clients. How do I enter these expenses? I've tried adding them as "Subcontractor Costs", but Freeagent comes back with:

1 ERROR PROHIBITED THIS EXPENSE FROM BEING SAVED

There were problems with the following fields:

Expense type is not valid for this company