I'm ok with registering, I'm based in UK ..... anyway I didn't know things changed back in May 2018.
( I just did just quick search on google and come across )
In the past .uk domains registered to an overseas address required a service address in the UK which could not be a PO box.
Since May 2018 the service address is no longer required, so you should be fine to register the .uk domain assuming the Right of Registration does not belong to another registrant. ref
I'm ok with registering, I'm based in UK ..... anyway I didn't know things changed back in May 2018.
( I just did just quick search on google and come across )
In the past .uk domains registered to an overseas address required a service address in the UK which could not be a PO box.
Since May 2018 the service address is no longer required, so you should be fine to register the .uk domain assuming the Right of Registration does not belong to another registrant. ref