I have all my clients sorted in a sheet with column A containing month 1, 2,
3, 4, up to 12 - then column B has the client code, column C client Surname
and Name.

I need to insert 2 rows after each client and need a code to be able to do
this as there are over 500 clients.

I have filtered to show unique on column B, and to do a simple keystroke is
DOWN, DOWN, DOWN, INSERT ROW, INSERT ROW.

The problem is that some clients started and ended at various times during
the year, so not all have the same number of entries.