LHR
LHR - just the top off my head, mostly just T2 and T3. idk T4. might be wrong on some.
DNATA
Emirates
Cathay
All Nippon
Iran Air
LATAM
PIA
MEA
Philippine
Garuda (probably still do as they moved to T4)
Singapore
COBALT
Delta
Qatar
Etihad
JAL
Virgin Atlantic
MENZIES
New Zealand
Avianca
Aer Lingus
Air Canada
Asiana
Air China
American (ramp,pushback only)
Austrian
Beijing Capital
Brussels
Egyptair
Ethipioan
Eurowings
EVA
Finnair
Hainan
Icelandair
Lufthansa
LOT
Qantas
Jordanian
Shenzhen
South African
Sri Lankan
Swiss
TAP
Tianjin
Turkish
SWISSPORT
SAS
Flybe
Croatian
AZZURRA
Air India
Thai
United - independent
Vueling-Iberia-BA