I also tried to do this, but then I was told that such a function was not provided. It was a disappointment of the year to me. Here is a (link hidden) of one of the best financial software development services and by giving the link of this company, I hint it would be a good idea to contact these guys for such a function to appear.

I want to add financial year in invoice prefix number and the financial year needs to upgraded automatically after a cycle.

Please suggest how to do it?