Invoice from Time booked on Project

We are a service company, booking time on projects.
The projects can take up to few years, but we are creating monthly invoices.

is there any possibility to create invoices based on open (not billed) times on projects?

Hi, could you illustrate with screenshots to help other understand you better?

You have the option of creating invoices from timesheets. This will be booked to your project as well:

We are currently evaluating ERPNEXT, thus i have no screenshots ATM, sorry.

What we are trying to achieve is:

Employee A is Booking 20 Hours to Project Z
And Employee B is Booking 25 hours to Project Z

End of the month i want to create an invoice out of it: with a total of 45 hours.

Hi Kenneth, i saw that. but isnt that for a specific timesheet from one employee only?

While timesheet is made per employee, you can add multiple of them in an invoice:

Do try to play around with this option

Can i add somehow multiple timesheets at once?

Yes, you should be able to: