Hi Anne -
We do offer per diems for project employees, but not contractors.
For contractors that would be considered a reimbursable expense and they would need to invoice for it. We have not had to cross that bridge yet but think we would add rate detail in the contract agreement under the payment clause.
We use the same per diem rate that we have in our employee handbook. We use the same handbook for our employees as we do for project employees.
Happy to chat further.