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Choosing a mobile plan

Which network does my SIM provider use?

Short answer

SMARTY uses Three, giffgaff uses O2, and Lebara and VOXI use Vodafone. Other SIM brands also use a larger network's infrastructure. The table identifies the network to check before you choose a plan. A shared network name alone does not establish that two plans have identical features or performance.

Check local coverage with Ofcom

Updated

Find my SIM provider

Start with the network, then check the signal and the plan's terms.

UK SIM providers and their named networks

SIM providerNetwork to check
1pMobileEE
Lyca MobileEE
giffgaffO2
Sky MobileO2
Tesco MobileO2
iD MobileThree
SMARTYThree
LebaraVodafone
TalkmobileVodafone
VOXIVodafone

Where do these network names come from?

Ofcom lists the networks used by these SIM brands. SMARTY and giffgaff also name their networks on their own pages. Sources checked on 11 November 2026.

  • Use the named network as the starting point for a coverage check. Confirm the particular SIM brand's current coverage and features before ordering.
  • The table identifies network relationships. It does not rank signal quality, compare prices or promise identical service between brands.
Sources (3)

How do I check whether it will work where I need it?

Check home, work and other places you use your phone on Ofcom's Map Your Mobile, then check the SIM provider's own map. Predicted coverage is a guide, not a guarantee inside a particular building.

  1. 1

    Find the network

    Look up your SIM brand in the table.

  2. 2

    Check the places you use it

    Compare indoor and outdoor coverage on Ofcom's map.

  3. 3

    Check the actual plan

    Confirm phone compatibility, calling features, data and roaming with the provider.

Sources (1)
Open Ofcom's coverage checker

Can I change SIM provider and keep my number?

Ask the new provider to confirm number transfer for the exact plan before buying. For a transfer between providers, Ofcom says to text PAC to 65075 and give the code to the new provider. A PAC lasts 30 days.

  • Text INFO to 85075 to check your contract position and possible early termination charge.
  • Changing plans within the same provider can follow its own process. Confirm the route before cancelling anything.
Sources (1)

Questions about choosing a SIM network

Which network does SMARTY use?

SMARTY says it is powered by Three and supports 4G and 5G. It does not support 2G or 3G. Check its coverage map and your phone's compatibility before ordering, especially if you use an older handset.

Which network does giffgaff use?

giffgaff says it is powered by O2. Start with O2 on Ofcom's coverage checker, then confirm the coverage and features of the giffgaff plan you are considering. Choose the allowance and contract terms for your own usage.

Does a cheaper SIM on the same network guarantee the same service?

The network name alone is not enough to make that promise. Check the exact plan's coverage, phone compatibility, calling features, roaming terms and any speed limits with the provider. Compare the total cost alongside those features before choosing.

Do I need a PAC before comparing SIM-only plans?

No. You can compare plans before requesting a PAC. When you decide to move your number, Ofcom says to text PAC to 65075 and give the code to the new provider. Check that the chosen plan accepts the transfer before buying.

Choose the plan as well as the network

Check contract costs, number transfer and coverage before committing.

Start here

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How mobile comparison works with Taupia.

Compare SIM-only plans

Choose your data needs and compare available plans with Taupia. You can start without a postcode, address or PAC. Complete any purchase with the provider after checking its terms.

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Cite this page

Taupia. "Which network does my SIM provider use?". Last updated 11 November 2026. https://taupia.com/compare-mobile-prices/which-network-does-my-sim-use