How to Change the Rate in a Contractor Request requisition in Services Procurement?

 Hi,

I have created a Contractor Request in Services Procurement via iProcurement using "Rate Based Temporary Labor", ie. $125/hr, Amount=$10,000

A PO is then created.

I need to change the Rate entered, however from iprocurement I can only change the Amount field when the Change Order process begins.

How may I update the Rate value from Services Procurement?

I can update the rate in Oracle Purchasing from the purchase order directly, however I do not want the requestors to have access to the form.

Thanks

Maurice