What happens to billable time of a shared task (task in multiple projects)?

In Asana, a task can be shared with several projects. What happens to the billable time and amount of such a task? 

What happens if a task belongs to 2 clients with different rates.

Let's set up 2 clients with different rates:

• Client A > Project А = $100/h;
• Client B > Project B = $50/h.

This is what we'll see in our report:

• Time shows for every project and client to which a task belongs, but the total is not doubled; 
• Billable Amount is calculated by the higher rate of Project A. 

If, for instance, we'll modify the rate of Project B to $500/h, the report result will change to this:

The logic with invoices is slightly different. This is what we see making an invoice for Client A, where rate = $100/h:

And this is the second invoice where our project has a rate of $500/h:

• When you generate an invoice, we take the project rate which appears in this invoice;
• I can create an invoice with time from the shared task for Client A and B. The task's time can appear in any of this invoices, however, when the invoice for one client is created, its time is marked as "invoiced" and can't be included into the invoice of another client. 

Well, the drawback with such approach is that my report will show false results when I first create an invoice for a client with a smaller rate. Unfortunately, we have not found a solution for such cases yet.

How to include time of a shared task in a particular project

There is an option to select particular project when creating an invoice. If you figure out that you made a mistake and want your time to fall under another invoice, you have to remove the previous invoice. Additionally, you can move time from one project to another before creating an invoice.