If the license of your data sets permits it and is compatible with our cc-by license then you can post it to this thread or send it to me via email. i will then add it to the postal code table. Thanks a lot.
If you have collected the data yourself then you can define the license you want to release it under. A single postal code is just a number and cannot be copy-righted, but collecting a lot of codes can be a lot of work and thus the collector can decide under which license he wants to give his work to others.