diff --git a/include/prefix.cpp b/include/prefix.cpp
index d24e3ec66..7e4b117b7 100755
--- a/include/prefix.cpp
+++ b/include/prefix.cpp
@@ -171,6 +171,19 @@ void TPrefix::set(const char* name, bool force, TFilelock mode)
   }
 }
 
+bool TPrefix::exist(long codditta) const
+{
+  CHECKD(codditta > 0, "Solo le ditte con codice maggiore di zero possono esistere : codice", codditta);
+  TFilename s(firm2dir(codditta)); s << "/dir.gen";
+
+  if (fexist(s))
+  {
+    s = s.path();
+    s << "/trc.gen";
+    return fexist(s);
+  }
+  return FALSE;
+}
 
 bool TPrefix::test(const char* s) const
 {
diff --git a/include/prefix.h b/include/prefix.h
index e88d8bbd4..72615cc67 100755
--- a/include/prefix.h
+++ b/include/prefix.h
@@ -33,6 +33,7 @@ class TPrefix : public TObject
 public:
   // @FPUB
   void set(const char* name = NULL, bool force = FALSE, TFilelock mode = _manulock);
+  bool exist(long codditta) const;
   bool test(long codditta) const;
   long get_codditta() const ;
   bool set_codditta(long codditta, bool force = FALSE);