Networks & SIM Cards

WhatSIM offers all the major UK networks to make sure we have the right choice for anyone's needs. If you already know which network you want, or just wish to learn more about them, click on their logo below.

Orange and T-Mobile have combined to form EE, the UK's biggest and fastest 4G network.

O2 SIM Only
Three SIM Only
Vodafone SIM Only
giffgaff SIM Only deals from £5
Tesco SIM Only
Virgin SIM Only
The People's Operator SIM Only deals from £4.99
TalkTalk Mobile


Filter our deals down to just the ones that work for your phone!

Not ready to take the plunge? Why not take a look through our Buyers Guides first?


SIM Types

Standard SIM / Mini SIM for phones
Having been around the longest, it fits most older handsets. Measures 25mm x 15mm x 0.76mm. More info...
Micro SIM for phones
Used in most recent smartphones including HTC, Nokia, Samsung, Sony and older versions of the iPhone (4s and older). More info...
Nano SIM for phones
Designed for the latest raft of ultra-slim phones like the iPhone 5s and HTC One. Measures 12.3mm x 8.8mm x 0.67. More info...