In the
Great_BritainPostal.ver
file you can see the version.The latest is the
[Description]
ID=GreatbritainPostal_TeleAtlas
Version=965
With Notepad, you can open the ver file.
If you can not find the newest addresses then you have to wait for the next update
970.
It can take up to a year or even longer before you find the newest addresses and even then it is possible that you not find them. I think it is not a priority item for TomTom because they depended on the information from general and local counsels.
You have not 100 % guarantee that you got the latest postcodes.