The BBC actively tracks incoming connections from Tor users by monitoring for IP addresses from known Tor (exit) relays.
The following is an excerpt of a response from BBC customer support. It's a year old, but if they were tracking and blocking things back then, it's highly likely they still will be now. (January 2016.)
Dear Mr ....
Thanks for contacting the BBC iPlayer Support Team. I'm sorry for the
delay in replying.
Although it's been a while since you contacted us, I want to reassure
you that we did read your contact shortly after it was received. We
check all the contacts sent to iPlayer support every morning, and if
we spot a potential fault we'll escalate for further investigation.
We understand you are encountering issues accessing BBC iPlayer. We
sent this across to our technical team for further investigation and
they have stated that there is evidence this IP is a Tor. No changes
will be made at this time to this IP. You will need to stop using a
Tor network so we can verify that you are in the UK and you will then
be able to access iPlayer services.
At present, Tor nodes are classed as proxies, regardless of whether or
not they are an exit node. We are working to differentiating Tor exit
nodes from non-exit relays, to allow us to block exit nodes only.
And... There are more recent news stories detailing how the BBC is blocking connections from any UK-based proxy, including VPNs, the aim being to ensure only people based in the UK who pay the licence fee (i.e. the money used to fund the BBC) can connect.
I believe the "You are not in the UK" message is the stock message they serve to people they believe are connecting from proxies.