Which mobile network has the best coverage in South Wales?

Last updated: 29 July 2022   By Dr Lucy Brown, Editor

Mobile coverage in South Wales varies depending on which area we're looking at and what type of mobile signal we need.

Voice coverage from at least one mobile operator is high across South Wales, with O2's network proving particularly resilient.

EE are the top choice for 4G data, although the Shared Rural Network programme is going to plug gaps from all operators across Wales.

However, 5G is yet to spread substantially across South Wales, with EE and Three so far providing the better coverage around urban areas.

south wales

Mobile coverage in South Wales

All four mobile networks have a strong presence in Wales, although the geography of more rural areas like Pembrokeshire and Monmouthshire make coverage trickier in places.

As the Ofcom data below shows, most areas of South Wales have voice and 4G data coverage from at least one operator, with many having coverage from multiple operators.

However, the detail of which areas are covered by which providers needs to be checked on the individual websites of the operators - and there are some notable gaps in coverage around rural areas.

5G in South Wales has yet to move beyond the busy urban centres, so mobile users looking for a decent 5G signal are generally out of luck if they're outside Cardiff, Swansea and Newport.

Check your signal with Ofcom's mobile availability checker.

Voice and text coverage

Winner: O2 has superior mobile coverage for calls and texts.

Full data from Ofcom's Connected Nations 2021 report shows how voice and text coverage fairs across the region.

For operator comparisons, we have to look at Wales as a whole. Here are the key figures about the four network operators published in September 2021:

EE O2 Three Vodafone
Geographic 86% 91% 87% 88%
Outdoor premises 99% 99% 99% 99%
All roads 82% 88% 84% 85%
Indoor premises 95% 98% 94% 97%

Based on this analysis, O2 is the best mobile operator for voice services in Wales. They have:

  • Higher geographical coverage
  • Better coverage along roads in Wales
  • More indoor premises coverage and are tied on outdoor premises

As the figures suggest, however, there are still areas where O2's network doesn't reach, and no provider is perfect on any metric.

That's why it's important to look at coverage across the South Wales region as a whole to find out where in the region customers may have difficulties making a voice call.

Below is the geographical coverage examining how much of the South Wales landmass is covered by mobile operators. This table is ordered by local authority area:

At least one All operators Complete not spots
Blaenau Gwent 100% 98% 0%
Bridgend 100% 97% 0%
Caerphilly 99% 98% 1%
Cardiff 100% 100% 0%
Carmarthenshire 97% 82% 3%
Merthyr Tydfil 99% 90% 1%
Monmouthshire 97% 80% 3%
Newport 100% 99% 0%
Pembrokeshire 99% 89% 1%
Rhondda 100% 91% 0%
Swansea 99% 93% 1%
Torfaen 100% 97% 0%
Vale of Glamorgan 100% 97% 0%

There are only a few areas classed as complete not spots as far as voice and text coverage in South Wales goes.

However, outside of the big urban areas, there are still locations where all operators have yet to reach. This means that, for people living or visiting those areas, it's still important to check the individual town or village to see how an operator's voice and text coverage holds up.

Remember, too, that indoor premises coverage can be different even if geographical coverage is high or low.

This is because the population isn't spread out over the whole landmass but generally concentrated in specific areas that will be covered by mobile masts.

As an example, here is the indoor premises coverage for voice/text in two areas that are well covered by multiple operators (Cardiff and Newport) compared to two with high levels of not spots (Carmarthenshire and Monmouthshire):

At least one All operators Complete not spots
Cardiff 100% 99% 0%
Newport 100% 96% 0%
Carmarthenshire 98% 83% 2%
Monmouthshire 98% 87% 2%

Both Cardiff and Newport see a slight drop in coverage from all operators when we move indoors, while Carmarthenshire and Monmouthshire see an increase.

Again, it depends on why a customer is checking for coverage. Residents will need stellar coverage both inside and outside their home while visitors might be more concerned with the amount of geographical coverage to make calls in the event of an emergency.

4G coverage

Winner: EE offers better coverage for 4G customers.

Being able to access data services through the 4G network is a crucial part of life for most people.

However, these networks are not as widespread as voice networks, and there are still some areas that have only one or two operators available.

Again, we have operator comparisons available for all Wales in the following table:

EE O2 Three Vodafone
Geographic 84% 72% 77% 72%
Outdoor premises 99% 98% 96% 97%
All roads 79% 73% 70% 70%
Indoor premises 93% 91% 85% 89%

EE is the best network in Wales when it comes to 4G services. In fact, they are significantly ahead of their rivals on several key points:

  • They are 7% clear on geographic coverage
  • They have 6% more coverage on all roads compared to their nearest rival
  • They have 2% better indoor premises and 1% better outdoor premises coverage

Across all these metrics, then, it's more likely that EE is going to be the best operator in Wales for 4G coverage.

Regional variations will apply and it's important to check postcodes using Ofcom's official postcode checker to see how 4G indoor/outdoor coverage fairs in a given area.

Again, we have local authority data that shows the level of coverage from at least one and all operators at a local level. Here is the data on geographic area:

At least one All operators Complete not spots
Blaenau Gwent 100% 92% 0%
Bridgend 99% 91% 1%
Caerphilly 98% 92% 2%
Cardiff 100% 97% 0%
Carmarthenshire 94% 63% 6%
Merthyr Tydfil 97% 78% 3%
Monmouthshire 93% 59% 7%
Newport 100% 96% 0%
Pembrokeshire 98% 74% 2%
Rhondda 97% 77% 3%
Swansea 98% 85% 2%
Torfaen 98% 87% 2%
Vale of Glamorgan 100% 85% 0%

One of the first things that jumps out here is that, while many areas have high levels of 4G coverage from at least one operator, the percentages for all operators are significantly lower in some cases than we saw for voice calls in the section above.

Well-populated areas like Cardiff and Newport maintain 100% coverage from at least one operator, although only 97% and 96% respectively from multiple operators.

For more rural parts of South Wales like Monmouthshire and Carmarthenshire, the drop is far more pronounced, and all operators only cover 59% and 63% of those local authority areas.

So, mobile users will need to check their 4G coverage carefully, especially if they are visiting rural areas of South Wales.

It's also working taking a look in full at the indoor premises coverage for 4G across the different local authorities:

At least one All operators Complete not spots
Blaenau Gwent 100% 85% 0%
Bridgend 100% 85% 0%
Caerphilly 100% 90% 0%
Cardiff 100% 92% 0%
Carmarthenshire 96% 65% 4%
Merthyr Tydfil 100% 82% 0%
Monmouthshire 96% 71% 4%
Newport 100% 90% 0%
Pembrokeshire 96% 66% 4%
Rhondda 100% 77% 0%
Swansea 100% 79% 0%
Torfaen 100% 82% 0%
Vale of Glamorgan 99% 68% 1%

This table demonstrates that 4G coverage from at least one operator is available indoors at the majority of premises across South Wales.

There is the problem again of low figures for multiple operators in some areas, plus there are significant not spots in Carmarthenshire, Monmouthshire and Pembrokeshire.

Some local authorities also see a big dip in indoor coverage from multiple operators compared to the figures for geographic coverage.

In the Vale of Glamorgan, for example, 85% of landmass is covered by all operators whereas the figure drops to 68% for indoor premises.

5G coverage

Winner: EE has more concentrated coverage in urban areas but Three covers more ground.

It's when we look at 5G rollouts that South Wales mobile coverage issues become more apparent.

Ofcom's Connected Nations update published in Spring 2022 estimated the following 5G coverage levels in Wales as a whole:

  • 27-38% outdoor premises from at least one operator
  • 2-5% outdoor premises coverage from all operators

5G rollouts focus mainly on busy urban centres as these are the places where the population benefits most.

For South Wales, then, that means Swansea, Cardiff and Newport have 5G coverage from mobile networks, but most other locations get no coverage for now or are limited to one network.

Three currently has outdoor 5G coverage in more towns than other providers as the map below demonstrates:

three coverage in south wales

They have some 5G coverage around Abergavenny as well as more around Merthyr Tydfil and Treherbert.

However, Three's services are not as extensive as EE's around the major urban centres.

As the map below shows, EE has more concentrated 5G coverage around Swansea, Cardiff and Newport:

ee coverage in south wales

Meanwhile, Vodafone has more limited coverage around the South Wales urban hubs but their major patch of coverage elsewhere is a smattering in Builth Wells:

vodafone coverage in south wales

5G coverage from O2 is even more limited, with some coverage around Cardiff and Penarth as well as some around the Swansea area:

o2 coverage in south wales

Overall, customers looking for 5G services in South Wales will find more coverage with Three and EE, although the best network will depend on location and rollout plans.

We look more at this below.

Note: Ofcom don't yet analyse indoor coverage for 5G services, so the maps above are all focused on outdoor coverage. This means that, while there may well be good 5G coverage indoors in the dark green areas, this isn't guaranteed.

Learn more about 5G mobile broadband and which networks are best across the UK.

Future of mobile coverage in South Wales

Research published by the Welsh Government in October 2021 cautioned that improvements in 4G coverage had largely plateaued since 2018.

However, they were optimistic that the Shared Rural Network (SRN) plan implemented by the UK Government would reach the following promised targets by the end of 2025:

  • 80% coverage from all operators
  • 95% coverage from at least one operator

We've already seen moves to improve infrastructure under the SRN from major networks, with EE upgrading 76 sites in Wales in 2021 and 33 sites set to be installed and shared by O2, Vodafone and Three by 2024.

This should boost the 4G coverage across South Wales premises and roads as well as the rest of the country, although the threshold for 80% coverage from all operators mean customers may still be limited by their location when choosing a mobile network.

5G rollout

The Welsh Government was less optimistic about the prospect of 5G coverage spreading across Wales.

In their research, they pointed out that only 3% of the UK's 5G sites were located in Wales at the time of publication while Wales houses 5% of the UK's population.

Their concern is that the 4G gap will be narrowed but it may be replaced by a 5G gap without intervention.

A consortium project called 5G Wales Unlocked led by the Welsh Government is working in partnership with Monmouthshire County Council and Blaenau Gwent County Borough Council to explore the rural use cases of 5G.

By showcasing the benefits of 5G on rural businesses and tourism, the consortium is hoping to stimulate investment into the area - and one of the partners is BT, the owner of EE.

Verdict: Who's best for coverage?

The best mobile network in South Wales depends on what you're looking for and whereabouts in the region you are.

There are some overarching points we can make about coverage across Wales:

  • O2 has better voice and text coverage
  • EE is better for 4G coverage
  • 5G coverage is limited but Three and EE are likely to be the best options

As we've discussed in this guide, the detail of where you live, work or plan on visiting really matters, especially if you're looking for solid 4G coverage.

Thanks to the Shared Rural Network rollout plan, coverage from all operators is set to improve by 2025, but it won't result in comprehensive coverage from every provider, so customers in South Wales will still need to make some important decisions about which network operator they choose.

Mobile users struggling to make a call indoors may find mobile signal boosters useful - the rules on these are being overhauled in 2022 to make it easier for customers to improve their signal at home.

We've got more information on mobile coverage across other areas of UK in our dedicated guide.


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