Yes, I just entered the code and away I went. One thing I have noticed is that some order nos. begin gm-????? and others with on-????? I don't know if that makes a difference though. My original upgrade code (Dec 08) for a N96 was a 'on' number. I sent that back and phoned up for a xperia x1 and that was a 'gm' number (Jan 09). This 5800 was a 'on' number (Mar 09). My contract expiry date has moved to Sept. 14 2010.