You do not need a license to watch catch up, you need a license for as it is being broadcast, eg coronation street at 19.30 yes,watch it at 20.00 on a device other than a tv no.
basically if you have a tv you need a license, for a device,a laptop,iPad etc you don't.
been down every way there is to do this with enforcement from tv licenceing, its a very up hill battle to get the right information, they want everybody to have a license, and if you havnt got one they wont believe you until they vist,even using only cable or satellite broadcast you need a license, 
That is most definitely incorrect, as non TV devices can receive live TV (via streaming). A licence is definitely required for any live UK broadcasts. Obviously, even if you do not watch it live, a licence is still required if you record a broadcast for later viewing.
The grey area has come in because catch-up services have been envisaged and implemented since the laws were made, and loopholes found.
The problem is, most catch-up services also offer live streaming. How do you enforce that? The law needs tidying up to take account of current technology, and what is possible to police and enforce.
Simple solution would be to cut the beeb free, and do away with the licence fee. £150pa isn't really value, when you consider the vast majority of the tripe they think us retarded public want to watch - if you believe their figures, 1 in 4 adults watch knobenders regularly, and not even I believe the UK population is that desperate to watch dreary, depressing, poorly acted, poor scripted shite.
The flip side, £150pa isn't enough of a saving for the hassle of arguing the point if I didn't have one. We hardly ever watch live TV anyway, so moving away from recording here, and using streaming catch-up services would be easy enough for Mrs TB and I to adapt to, but really ain't worth the hassle of dealing with it.