Worth noting the article then says...
TV Licensing will have access to the information but the BBC says it will not be used for enforcement purposes.
...and in the analysis...
The BBC says the information won't be used for enforcement - but adds it may be in the future.
It certainly sounds like they're phasing in the ability to enforce the need to have a TV licence in order to watch iPlayer content. The post code could easily be faked, so I'm not sure how useful it'll be in restricting access to UK households. I suspect the only realistic way to enforce would be if you were also required to enter a TV licence registration number.
"Listen, we've all got something to bring to this conversation, but from now on what I think you should bring is silence." - Rimmer