Invoice a different customer in the project manager addon
In the project manager addon we can associate any invoice we want - regardless of the customer (and that's great),
But when we want to create an invoice via the project manager addon or to select Time Tracking entries and invoice them - the invoice is issued on the customer the project is Assigned To.
Since we work in a way that projects are paid by the man office while being done on a branch - we need a way to issue the invoice on another customer (i.e. the main office instead of the branch).
We can manually create the invoice and associate it to the project - but in that way the Time Tracking will not be set to billed.