Best Mobile Network For SIM Only Data

Customers looking for a new SIM only contract often look at the data allowance of a contract when comparing plans. Most SIM plans have unlimited calls and texts so getting a large data allowance can sometimes be the key to finding a good-value deal.

What is difficult is comparing the many, many different plans out there, given this we decided to take a snapshot of the market (25th June 2019) and compare the networks in what we hope is a fair way.

For each network we took the total GB across all of their SIM plans and the total cost to come up with a Cost-Per-GB figure (Not including Unlimited Plans). We've put everything in the table below for comparison and have put them in order from cheapest to most expensive

Three
Cost-per-GB: £0.46
Unlimited Plan: YES
Unlimited Cost: £22.00
Voxi
Cost-per-GB: £0.62
Unlimited Plan: No
Unlimited Cost: -
Virgin Mobile
Cost-per-GB: £0.69
Unlimited Plan: YES*
Unlimited Cost: £27.00
Vodafone
Cost-per-GB: £0.72
Unlimited Plan: No
Unlimited Cost: -
Sky Mobile
Cost-per-GB: £1.12
Unlimited Plan: No
Unlimited Cost: £-
EE
Cost-per-GB: £1.20
Unlimited Plan: No
Unlimited Cost: £-
BT Existing Customer
Cost-per-GB: £1.21
Unlimited Plan: No
Unlimited Cost: £-
O2
Cost-per-GB: £1.23
Unlimited Plan: No
Unlimited Cost: £-
Plusnet Existing Customer
Cost-per-GB: £1.12
Unlimited Plan: No
Unlimited Cost: £-
BT Standard
Cost-per-GB: £1.57
Unlimited Plan: No
Unlimited Cost: £-
giffgaff
Cost-per-GB: £1.89
Unlimited Plan: YES*
Unlimited Cost: £-
Plusnet Standard
Cost-per-GB: £2.13
Unlimited Plan: No
Unlimited Cost: £-
Smarty
Cost-per-GB: £2.58
Unlimited Plan: YES
Unlimited Cost: £18.75

*Notes:

As you can see above, there is a huge range of prices across all of the UK's major SIM networks. Some networks such as Three have chosen to focus on affordable data in order to attract customers hence the incredibly low average data price and with the UK's most-popular Unlimited data plan they are by far the cheapest.

The table also shows the obvious price-saving when choosing a 12 month SIM over Voxi, Smarty and giffgaff who provide only rolling 1 month plans. For some it can mean a large saving but on closer inspection the major networks charge a higher price for lower-allowance plans. For example 1 GB from Smarty costs £6.25 while the same 1GB from Vodafone costs £13.

When choosing a SIM contract it's therefore important to properly compare plans and know how much data you need for your regular use. In some cases it could mean £50-£100 difference per year.