4G LTE stands for Long Term Evolution. It's the fourth generation of mobile network technology, deployed in the UK from 2012. Most UK mobile traffic still runs on 4G, even on 5G-capable phones.
Speeds
Typical UK 4G LTE: 20-80 Mbps download, 5-25 Mbps upload. Latency around 30-50ms. Fast enough for streaming, video calls, gaming, and any normal use.
Coverage
4G LTE covers 99%+ of the UK population (combined across the four networks). It's still the most widely-available standard — 5G is catching up but not everywhere yet.
4G LTE vs 5G
For most phone use, the difference between 4G and 5G is invisible. 5G shines for very large downloads (HD video, big game downloads), low-latency cloud gaming, and crowded events (5G handles density better).