Official or unofficial, its the same disc, data and password, if your car doesn't have the correct background update level then you won't get 7 digit postcodes as the NAV can't handle them.
So then you'll have to pay for a vehicle update, unless you can blag it under some other warranty issue. (if you're in warranty)....
Your sig says you have an E46 is that right?
E63 AMG here at last!