B2B market ExpertMarket.co.uk's figures show that, as expected, O2, Vodafone and EE users in large cities such as London, Manchester, Nottingham, Edinburgh, and Glasgow do well with 99 percent coverage levels inside buildings and on roads.
Other coverage hotspots include Leicester (99 percent), Tyne and Wear (90 percent), Renfrewshire in Scotland (84 percent), and Merseyside (59 percent).
But even more towns remain stuck on zero coverage, including some noted as important tech centres, including Cambridgeshire, Brighton, East Sussex, Norfolk, Aberdeen, Dundee, and Inverness. Almost every rural in the UK area lacks any coverage.
Some towns that do have usable 4G coverage get it from a single provider, EE, including Cambridge, Birmingham, and Bristol. The latter seems to be a paradox issue as EE claims to offer 4G in Bristol despite Ofcom's figures recording it as zero percent on both premises and roads.
EE was the first network to offer 4G, launching its service in 11 cities in October 2012. Since then its rivals have launched services of their own, sometimes claiming coverage not borne out by external analysis.
According to Ofcom's November 2014 figures, data throughput will also vary by network and location in ways that are hard to predict. EE came top with an average download speed of 18.3Mbps, with O2 on 15.5Mbps, and Vodafone and Three tied on 11.4Mbps.
These speeds were between two and three times what was possible with 3G infrastructure but didn't always correspond to browsing speed which depends on other elements such as DNS resolution. Three was the fastest at 0.62 seconds on average to load a web page.
'These findings make it clear that phone companies are still favouring London, and many places across the UK are receiving a poor service as a result," said Expert Market director, Amy Catlow.
"It is not only troubling for people in terms of business, but must be very frustrating for individual users too, who might find it hard to stream or download while out and about."
Another issue is the number of 4G-enabled devices, with smartphone models more than a year old often not offering the capability.
Meanwhile, BT is in negotiations to buy EE while Three is said to be looking at O2, a consolidation which on the face of it should eventually accelerate 4G rollout at the possible expense of less competition and higher prices.
Since August, BT has offered 4G as an option on all its business plans, another reason it wants to get its hands on EE in the UK.