Verdict up front: if you are an O2 or Vodafone customer, or a giffgaff, Sky Mobile, Tesco Mobile, Lebara or Lycamobile customer running on those networks, and you live or work in a 500m² property with dropped calls, muffled speech and failed SMS, the G500 Mobile Booster at £300.96 (model MBG500gb) is the best O2 and Vodafone signal booster on the UK market.

It delivers 75dB of gain, an 8dBi directional panel outdoor antenna aimed at the nearest O2 or Vodafone mast, an 8dBi directional panel indoor antenna aimed at the main living or working area, a 15m coaxial cable, up to 20dBm EIRP output power, a noise figure of 4dB or better, and Ofcom licence-exempt UKCA and CE certification. It covers 500m² for voice and SMS only.

If your problem is slow 4G data, the C500 at £335 is the data equivalent. If your problem is dropped calls, no-one hears you, SMS booking confirmations fail to send, or customers cannot reach your pub by phone, the G500 is the right tool. This guide covers why O2 and Vodafone signal is weak in 500m² buildings, the difference between 900MHz, 1800MHz and 2100MHz, which MVNOs are supported, the installation steps, how the G500 compares to the C500, whether you can run both together, and how to cover basements and lofts.

O2 and Vodafone deliver roughly 86 percent and 84 percent 900MHz voice coverage outdoors across the UK, according to Ofcom's 2025 Connected Nations report. The gap between outdoor and indoor coverage is where the problem lives. A 500m² large home, whether it is a five-bedroom detached house, a period stone cottage, a village pub with a bar and function room, a small restaurant, or a two-storey office, has multiple thick external walls, suspended concrete floors, triple-glazed windows, cast-iron doors and internal partition walls.

A 900MHz signal entering from the nearest O2 or Vodafone mast loses 28 to 45dB by the time it reaches the centre of the building. At the front window you see 2 to 3 bars. At the rear function room, the basement bar or the loft office, you see zero. The phone either drops the call mid-conversation or boosts its own transmit power, which drains the battery and creates choppy audio.

This is not a phone problem, not a tariff problem and not a coverage problem at the mast level. It is a building penetration problem. O2 and Vodafone have built the network. The G500 pulls that marginal signal indoors and raises it to a reliable 3 to 4 bars across the full 500m².

UK cellular networks use three main frequency bands for voice and data. Band 8 at 900MHz is the low-frequency band used by O2 and Vodafone for 2G GSM and 3G UMTS voice and SMS. It travels the furthest and penetrates walls the best, losing only about 6dB through a brick wall and 12dB through a 450mm stone wall.

Band 3 at 1800MHz is used by EE for voice and by all operators for 4G data. It loses about 10dB through a brick wall and 20dB through stone. Band 1 at 2100MHz is used by Three for voice and 3G, and by all operators for 3G data. It loses about 14dB through a brick wall and 24dB through stone.

The G500 is tuned exclusively to Band 8 900MHz. That is why it is the best O2 and Vodafone signal booster: O2 and Vodafone voice rides on 900MHz. It is also why the G500 does not work on EE, which uses 1800MHz, or on Three, which uses 2100MHz. For O2 and Vodafone customers, 900MHz is the voice band, and a booster tuned to anything else is boosting the wrong frequency.

giffgaff is a mobile virtual network operator (MVNO) that runs entirely on O2's infrastructure. Sky Mobile also uses O2's network. Tesco Mobile is another O2 MVNO. If you are a giffgaff or Sky Mobile customer, your voice and SMS ride on the same O2 900MHz Band 8 network as a direct O2 customer.

The G500 amplifies the 900MHz band regardless of which SIM is in your phone, so a giffgaff customer gets exactly the same improvement as an O2 customer. You do not need to tell the booster your MVNO. You do not need a different model. The G500 at £300.96 works identically for O2, giffgaff, Sky Mobile and Tesco Mobile.

Lebara and Lycamobile are MVNOs that run on Vodafone's network. They broadcast voice and SMS on Vodafone's Band 8 900MHz channel. The G500 amplifies that channel in exactly the same way it does for a direct Vodafone customer. If you use Lebara or Lycamobile in a 500m² property, the G500 will improve your calls and SMS identically.

This means a household, pub or office with mixed carriers, say O2 on the manager's phone, giffgaff on the bar staff phone, Lebara on the chef's phone and Sky Mobile on the landlord's personal phone, only needs one G500 unit. It boosts every O2 and Vodafone network connection simultaneously, for unlimited users.

The G500 is rated for 500m² of indoor coverage. That covers several distinct property types. A five-bedroom or six-bedroom detached house over two floors, around 250m² per floor, with a kitchen diner, multiple reception rooms, a basement and a loft conversion. A period stone cottage or Georgian townhouse with 450mm solid walls, sash windows and two or three storeys. A village pub with a front bar, a rear function room, a cellar and a first-floor dining area. A small restaurant with a front of house, kitchen, store room and outdoor seating. A small two-storey office with around 250m² per floor, meeting rooms and a server room.

In every one of these scenarios, the G500's 75dB gain, 20dBm EIRP output and dual 8dBi directional panels deliver a reliable 3 to 4 bars of 900MHz voice signal. The key requirement is at least 1 bar of outdoor 900MHz signal at the antenna position.

Yes. The G500 carries UKCA and CE certification. It is Ofcom licence-exempt, which means you do not need to apply for a licence to install it at your home or business. Ofcom's regulations permit licence-exempt signal boosters on Band 8 900MHz as long as the unit meets defined power and spurious emission limits.

The G500's 20dBm EIRP output power, built-in automatic gain control (AGC), and manufacturer-tuned filters keep it within those limits. It will not interfere with the O2 or Vodafone network, and it will not cause harm to the cell tower.

The G500 ships as a DIY kit. The booster unit is 200 by 150 by 35mm and weighs 500g. The kit includes the booster unit, a 15m coaxial cable, the outdoor 8dBi directional panel, the indoor 8dBi directional panel and fixings. Most customers complete the installation in 45 to 60 minutes with a drill, a screwdriver and a short ladder.

Step 1: Find the nearest O2 or Vodafone cell tower

Use a phone signal reading app or walk around the outside of the building to find the side with the strongest 900MHz signal.

Step 2: Mount the outdoor 8dBi panel

Mount the outdoor panel on a chimney bracket, gable-end wall or roofline mast, aiming it directly at the nearest mast. Run the 15m coax cable through a drilled wall hole with a rubber grommet.

Step 3: Mount the indoor 8dBi panel

Mount the indoor panel on an interior wall or ceiling, aimed at the main living area, the bar, the dining room or the open office. Keep the indoor booster unit at least 8 to 10 metres from the outdoor antenna to prevent oscillation.

Step 4: Power on and let AGC tune

Plug the booster into an unswitched 240V UK mains socket. The AGC automatically tunes the gain. The LED confirms power and signal lock. The unit draws under 15W.

The G500 and the C500 are both rated for 500m² and both deliver 75dB gain. The difference is what they amplify. The G500 at £300.96 is a voice and SMS booster. It amplifies Band 8 900MHz 2G and 3G signals for O2, Vodafone, giffgaff, Sky Mobile, Tesco Mobile, Lebara and Lycamobile. It does not amplify 4G LTE data or 5G.

The C500 at £335 is a data booster. It amplifies 4G LTE bands for mobile internet, faster browsing and better indoor data speeds. It is the right product if your problem is slow mobile internet, not dropped calls. Both units share the same 75dB gain, 500m² coverage, dual 8dBi panel antennas, 15m cable, 20dBm EIRP and 4dB noise figure. If your problem is dropped calls, choose the G500 at £300.96. If your problem is slow 4G data, choose the C500 at £335.

Some customers have both problems: dropped calls and slow data. The G500 and C500 can be installed together, but they need careful physical separation. Because both units use panel antennas, the outdoor antennas should be mounted at least 3 metres apart on the chimney or gable, and aimed in the same direction at the nearest mast.

The indoor antennas should also be separated, mounted on different walls or on opposite sides of the main room, to prevent the two amplified signals from feeding back into each other. When installed correctly, the G500 boosts voice on Band 8 and the C500 boosts data on 4G bands, giving a full indoor cellular solution. When installed poorly, they can cause oscillation and actually degrade the network. If you need both, talk to the support team about the best antenna placement before drilling.

The G500 is one of the few voice boosters powerful enough to reach below-ground and above-rafter rooms. A basement bar, cellar or wine store sits under a suspended concrete slab that absorbs 900MHz signal heavily. The G500's 75dB gain and 20dBm EIRP output push signal through that slab. Aim the indoor 8dBi panel down the stairwell or mount it on the ceiling above the basement access, and the directional beam carries into the below-ground room.

A loft conversion or first-floor office sits 8 to 11 metres above ground. Mounting the outdoor panel high on the roof ridge improves the incoming signal, and the high output power carries the amplified signal up through two floors. Most 500m² customers report that the G500 covers the ground floor, first floor and basement reliably, with the loft room at the edge but still usable.

We compared the G500 against four alternatives for O2 and Vodafone customers in a 500m² property.

For customers who want to squeeze every extra bar out of the G500, we recommend four upgrades.

Tip 1: Extend the outdoor cable to 20m or 30m

Mount the panel on a mast rather than a chimney bracket, which raises the antenna above neighbouring trees and rooflines.

Tip 2: Fine-tune the outdoor panel angle

Use a signal reading app to adjust the outdoor panel in 5-degree increments while watching the dBm reading on your phone. A 10-degree turn can change the signal by 3 to 5 bars.

Tip 3: Keep the indoor panel clear of obstructions

Do not mount the indoor panel behind a TV, fridge or metal cabinet, because those objects block the directional beam.

Tip 4: Use an unswitched fuse spur

Plug the unit into an unswitched fuse spur rather than a wall socket controlled by a light switch, so it never loses power overnight. The G500 draws under 15W, costing roughly £4 per year in electricity.