It would be fantastically helpful if you could share a workbook it would be great. I mocked up a sample and I did not have issue with plotting these.
Did you by chance have nulls? (X unknown grey pill in the bottom right hand corner?)
If so left-click that and choose edit locations.
If you do not have a field that uses the country geographic location in your view you will be using your default workbook locale location. Example: I am in the United Kingdom. It would automatically try to find each postal code in the UK for me instead of looking at other countries if I did not have a field named Country.
Send some dummy data, just a list of your postal codes/country should work and I'll look at it.
Thanks for looking at this Carl. I have spent two days trying everything possible...
For the UK Tableau is working perfectly, but it is not recognizing BE or NL postal codes. There are many cases where BE and NL have the same postal code, since they are both 4 digit. However, I would expect Tableau to accept duplicate postal codes in different countries (e.g. US, Mexico, France, Italy, Germany all have 5 digit postal codes which I would expect Tableau to be able to handle without any problems). You can see the screenshots below.
I've attached the file which shows country codes and postal codes. Let me know if you have any ideas.
I am using Tableau 9.3.2, I only have 102 unknowns from the list. I was able to plot nearly all of them on the map. Maybe you sent me a smaller data set, if not I'd recommend double checking that you are using 9.3.2.
I've tracked half of the UK unknowns and all of the BE unknowns and a few random ones from NL. All of these are non-geographic post codes. They are used for direct campaigns and mail sorting only so they would not have a set geographical location. I'm not going to run through a bunch of NL codes to confirm this. I also found that NL codes are often sorted as four numbers followed by two letters of the alphabet. I'm not sure if tableau is looking for this level of detail or not.
It could be that we've explained the Belgian and the UK issues but not the NL.
Apologise that this isn't a full solution but it should be on the right path to helping you solve these issues you're having.
Thanks Carl. I am not sure why it wouldn't work for me. I definitely have version 9.3.2. In the end I just uploaded the geocoding and did it the old way... Thanks for all your help.