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    giffgaff signal boosters for business premises

    giffgaff runs on the O2 network, so a booster that carries O2 fixes giffgaff signal too. We survey, design, install and support operator-approved CEL-FI systems across the UK.

    • Ofcom-compliant and legal
    • Single-network or all four networks
    • 4G and 5G
    • Installed and supported UK-wide

    Your free signal assessment

    An engineer measures your building and tells you exactly what will fix it.

    1. giffgaff signal, room by roomWhere it drops, and by how much.
    2. The best donor signalWhere the outdoor antenna should go.
    3. A design and a fixed quoteNo obligation, no surprises.

    ✓ Backed by our 3-month money-back guarantee →

    The problem

    Why giffgaff signal drops indoors

    giffgaff customers use the O2 masts. When O2 signal can’t get through the walls, giffgaff calls drop and data stalls, even with full bars outside.

    Thick walls and coated glass

    Modern buildings stop the O2 signal giffgaff depends on.

    Basements and lower floors

    Below ground there is often no signal at all.

    Mixed providers

    Staff and visitors use several different networks.

    Busy city centres

    Tall neighbours leave dead spots, even in big cities.

    1 · Donor antenna on the roofCEL-FI2 · Network unit3 · Indoor antennas on every floor
    How it works

    Outdoor O2 signal, brought inside for giffgaff users

    1. CaptureA donor antenna on the roof picks up the strongest O2 signal we measured during the survey.
    2. Clean and amplifyA Nextivity CEL-FI unit boosts that signal without interfering with the network or your neighbours.
    3. SpreadSmall indoor antennas cover every floor, so phones get full signal wherever people work.
    O2 network onlyA single-network system for O2, which also serves giffgaff and other O2-based providers.
    All four networksEE, O2, Vodafone and Three from one system, for staff and visitors on any provider.
    What happens next

    From survey to full signal, usually in weeks

    One team does the whole job, so there is one point of contact from the first call to ongoing support.

    1. 1SurveyWe measure giffgaff signal inside and out.
    2. 2Design and quoteAntenna plan and a fixed price.
    3. 3InstallOur own engineers, with minimal disruption.
    4. 4Test and hand overWe prove the coverage before we leave.
    5. 5MonitorOptional 24/7 signal monitoring. Learn more
    Measured results

    O2 signal before and after our installations

    We survey every building before and after installation with our own survey app. These are real O2 readings from recent projects.

    20installations measured before and after on O2
    +19 dBmedian signal gain
    26% → 97%of each floor with usable signal (better than −107 dBm)
    Business centre unit
    UK · 1 floor · Dec 2025
    Before-127 dBm
    After-75 dBm
    Usable O2 signal: 0% → 100% of the floor
    Neko Health
    Health clinic · London · 1 floor · Jul 2025
    Before-120 dBm
    After-86 dBm
    Usable O2 signal: 0% → 100% of the floor
    Estate agency office
    London · 2 floors · Jun 2025
    Before-123 dBm
    After-84 dBm
    Usable O2 signal: 0% → 100% of the floor
    Medical Research Council
    Research laboratory · Cambridge · 2 floors · Jan 2026
    Before-117 dBm
    After-88 dBm
    Usable O2 signal: 0% → 93% of the floor

    Average signal strength (RSRP) across each surveyed floor. Usable means better than −107 dBm, the level phones need for reliable calls over 4G.

    FAQ

    giffgaff signal boosters: common questions

    Which network does giffgaff use?

    giffgaff uses the O2 network, so any booster that carries O2 also improves giffgaff signal. You don’t need a separate system.

    Are signal boosters legal in the UK?

    Yes, if they meet Ofcom’s rules. Since the Wireless Telegraphy (Mobile Repeater) (Exemption) Regulations 2018, approved single-network boosters can be used without a licence. Multi-network systems need the networks’ consent, which we arrange. Unapproved boosters bought online are illegal, and Ofcom can act against anyone using one.

    How long does installation take?

    It depends on the size of the building. The quote includes an installation plan, and we work around your opening hours to keep disruption low.

    Can one system cover every network?

    Yes. A multi-network CEL-FI QUATRA system covers EE, O2, Vodafone and Three, so staff and visitors get signal whichever network they use.

    Will a booster work if there is no signal outside?

    A booster needs some outdoor signal to work with. The survey finds the strongest signal around your building. If there is none, we will tell you and suggest the alternatives.

    Ready for full giffgaff signal?

    Book a free signal assessment and get a design and fixed quote.

    Get a free signal assessment