How can I create a project with no rate and no budget for internal activities?

How can I create a project with no rate and no budget for internal activities?

Hello, 
I use zoho invoice for a consultancy company. 

we book project hours with a rate and a budget. 
we also book hours on "non billable" internal activities. 

ATM I need to create a project with 1€ rate and no budget to log my "non billable" internal hours. 

How can I create a project without a rate and a budget?