Boost4U G100 Review: Best Call Signal Booster Under £80 in the UK?
After 30 days of real-world testing in a rural Devon cottage with 1-bar O2 signal, the Boost4U G100 (£75.00) delivered a consistent 5-bar indoor voice signal on Band 8 (900 MHz), reduced dropped calls from 18% to under 2%, improved SMS delivery from 72% to 100%, and earned our verdict as the best budget call signal booster under £80 in the UK for O2 and Vodafone users — provided you only need voice calls and SMS, not 4G/5G data.
This review is based on hands-on testing, not marketing claims. We installed the G100 in a stone cottage, ran 50 test calls over 30 days, measured signal strength at multiple indoor points, tested SMS delivery, and compared it against three alternatives in the same price bracket.
Quick Summary: Boost4U G100 at a Glance
| Specification | Boost4U G100 |
|---|---|
| Price | £75.00 GBP (was £95.00, save 21%) |
| Type | Band 8 (900 MHz) Mobile Call Signal Booster |
| Frequency | Band 8 — 900 MHz (GSM / UMTS) |
| Max Gain | 60 dB |
| Coverage | Up to 100 m² |
| Networks | O2, Vodafone, giffgaff, Sky Mobile, Tesco Mobile, Lebara, Lycamobile |
| Services | Voice calls + SMS (no 4G/5G data) |
| 5G Support | No |
| Installation | 10–15 minutes, plug-and-play |
| Return Policy | 365-day money-back guarantee |
| UK Shipping | Free (10–15 business days) |
| Certification | UKCA / CE / Ofcom licence-exempt |
| Our Rating | 4.5 / 5.0 |
Unboxing: What You Get
| Component | Details |
|---|---|
| Booster Unit | 170 × 110 × 30 mm aluminium housing, LED indicators, two N-type connectors |
| Indoor Whip Antenna | 3 dBi, screws directly onto booster |
| Outdoor Omni Antenna | 5 dBi, weatherproof, with mounting bracket |
| Coaxial Cable | 5 m low-loss, N-type to N-type |
| Power Adapter | UK 3-pin plug, 12 V / 1 A |
| Mounting Kit | Bracket, screws, wall plugs |
| Documentation | Quick Start Guide (English) |
Build quality is solid for the price. The aluminium booster unit feels robust and dissipates heat well — after 72 hours continuous, the casing measured 37 °C. The antennas are plastic but durable. The 5 m cable is standard RG-58 grade, adequate for the included length.
Installation: Step-by-Step (Timed)
We timed installation from unboxing to first boosted call: 11 minutes and 20 seconds.
- Found best outdoor signal spot (2 min): Walked around the cottage with a phone on a call. Strongest spot was near a first-floor window facing the nearest O2 mast (1.5 km away).
- Mounted outdoor antenna (4 min): Screwed the omni antenna to the window frame using the bracket. Used the adhesive pad option for a rental-friendly install.
- Ran the cable (3 min): Fed the 5 m cable through the window seal.
- Connected booster (1.5 min): Screwed on indoor whip antenna, connected outdoor cable, plugged in power.
- Waited for sync (0.7 min): Power LED green immediately; signal LED solid green after ~40 seconds.
Total cost beyond £75: £0. No tools, no engineer, no subscription.
Performance Test Results
Signal Strength (dBm)
| Location | Before (dBm / bars) | After (dBm / bars) | Improvement |
|---|---|---|---|
| Living room (5 m) | -110 / 1 bar | -80 / 5 bars | +30 dB |
| Kitchen (10 m) | -114 / 0–1 bar | -91 / 4 bars | +23 dB |
| Bedroom (15 m, stone wall) | -118 / 0 bars | -99 / 3 bars | +19 dB |
Call Quality (50 test calls over 30 days)
| Metric | Before Booster | After Booster (G100) | Improvement |
|---|---|---|---|
| Dropped calls | 9 out of 50 (18%) | 1 out of 50 (2%) | -89% |
| Average MOS score | 2.8 / 5 (Fair) | 4.3 / 5 (Good-Excellent) | +54% |
| Calls with echo / distortion | 12 out of 50 (24%) | 2 out of 50 (4%) | -83% |
| SMS delivered within 10 sec | 72% | 100% | +28% |
Boost4U G100 vs Alternatives
| Feature | Boost4U G100 | Uncertified "Universal" Booster (~£35) | Boost4U C100 (£109.99) | weBoost Home Room (£349) |
|---|---|---|---|---|
| Price | £75.00 | ~£35 | £109.99 | £349 |
| Ofcom Compliant | Yes | No (illegal) | Yes | Yes |
| Bands | Band 8 (900 MHz) voice | "All bands" (interferes) | Band 20 (800 MHz) 4G | Bands 3,7,20 + 3G |
| Services | Calls + SMS | Claims all (unreliable) | 4G data + VoLTE | 3G + 4G data + calls |
| Coverage | 100 m² | Claimed 300 m² (actual ~20 m²) | 100 m² | 150 m² |
| Networks | O2, Vodafone + MVNOs | Claims all | All 4 UK networks | All 4 |
| Return Policy | 365 days | 30 days | 365 days | 30 days |
| Tested Gain | +30 dB at 5 m | +6 dB (oscillated) | +34 dB at 5 m | +31 dB at 5 m |
vs Uncertified "Universal" Boosters (£30–£50)
We purchased a top-selling "universal" booster for £34.99. Results:
- Indoor signal improved by only +6 dB (still 1 bar)
- Oscillated every 2–3 minutes, causing call drops
- Exceeded Ofcom's 17 dBm power limit — illegal to operate
- Plastic housing felt cheap; connector loosened after 2 days
Verdict: The £35 uncertified booster is a false economy and illegal. The G100 at £75 is the minimum price for a compliant, effective booster.
vs Boost4U C100 (£109.99)
The C100 is a 4G LTE Band 20 booster that improves mobile data and VoLTE calls for all four networks. It costs £34.99 more than the G100. If you only need calls and SMS on O2/Vodafone, the G100 saves you money. If you need 4G data or are on EE/Three, the C100 is the better choice. Many users install both for complete coverage.
vs weBoost Home Room (£349)
The weBoost is a multi-band premium unit costing 4.7x more than the G100. It offers 3G + 4G multi-band support but on Band 8 specifically, the G100 actually matched its call-quality performance. For pure O2/Vodafone call boosting, the G100 delivers equivalent results at a fraction of the price.
Pros of the Boost4U G100
1. Unbeatable Price
At £75.00, the G100 is the cheapest Ofcom-compliant mobile signal booster in the UK. Competitors start at £109.99 for 4G units and £349 for multi-band units. For users whose primary issue is dropped calls, the G100 solves the problem at the lowest possible cost.
2. Dedicated Call Quality Improvement
The G100 is optimised for Band 8 (900 MHz), the primary voice frequency for O2 and Vodafone. In our testing, it reduced dropped calls from 18% to 2% and improved MOS scores from 2.8 to 4.3. SMS delivery went from 72% to 100%. For call-centric users, this is exactly what matters.
3. Works with O2, Vodafone and All Their MVNOs
Because both O2 and Vodafone use Band 8 (900 MHz) for voice, the G100 covers O2, Vodafone, giffgaff, Sky Mobile, Tesco Mobile, Lebara and Lycamobile with one device. That is a large portion of the UK mobile market — approximately 40% of UK mobile subscribers are on O2 or Vodafone networks.
4. Genuine Plug-and-Play
11 minutes 20 seconds from box to boosted call. No app, no Wi-Fi, no account. The booster automatically detects and syncs with the Band 8 network. This is a major advantage for less tech-savvy users and for elderly customers who just want their phone to work.
5. 365-Day Money-Back Guarantee
Signal boosters are location-dependent. The G100's 365-day return policy gives you a full year to test it in your specific location. Competitors offer only 30–60 days. This is a significant risk-reducer, especially at the budget end of the market.
6. Free UK Shipping
Standard UK delivery is included in the £75 price. US brands like weBoost charge for shipping and may incur import duties and VAT, adding 20–30% to the total cost.
7. Low Power Consumption
The G100 draws approximately 4 W — less than a phone charger. Over a year of continuous use, it costs roughly £5 in electricity. It runs cool and can be left on 24/7.
Cons of the Boost4U G100
1. Calls and SMS Only — No 4G/5G Data
The G100 only amplifies Band 8 (900 MHz) for 2G/3G voice and SMS. It does not improve 4G LTE or 5G mobile internet speeds. If you need faster mobile data, you need a 4G booster like the C100. This is the G100's most significant limitation and the reason it is so cheap.
2. O2/Vodafone Only — Not EE or Three
The G100 does not work with EE or Three, which use Band 3 (1800 MHz) for voice calls. If you are on EE or Three, the G100 will not improve your signal at all. Check your network before buying. EE/Three users should choose the C100 4G booster.
3. 100 m² Coverage Limit
The G100 covers up to 100 m², which is one large room or a small flat. In our stone cottage test, usable 3+ bar coverage was approximately 75 m² due to thick walls. Larger homes need the C300 (300 m²) or a multi-antenna system.
4. Requires at Least 1 Bar Outdoors
A booster cannot create signal. If your outdoor signal is truly zero bars (below -125 dBm), the G100 will not help. In our test we had 1 bar (-110 dBm) outdoors, which was sufficient. Properties in very deep rural areas with no outdoor signal should contact their network operator.
5. Standard Cable Is 5 m
The included 5 m cable is sufficient for window-frame installation but may be too short if you need the antenna on the roof. Boost4U offers a 15 m cable upgrade for £30.99, adding to the total cost.
6. No Digital Signal Meter or App
The G100 uses simple LED indicators (power, signal) rather than a digital dBm meter or app. This makes it less precise for optimising antenna position. For most users, the LEDs are sufficient, but tinkerers may prefer the app-based premium units.
7. Standard Delivery 10–15 Days
Free standard shipping takes 10–15 business days, slower than Amazon Prime. If you need the booster urgently, express delivery is available at extra cost.
Who Should Buy the G100?
| Profile | G100 Suitable? | Why |
|---|---|---|
| O2/Vodafone user, dropped calls at home | Yes | Band 8 is exactly what O2/Voda use for voice; £75 solves the problem |
| giffgaff / Sky Mobile / Tesco Mobile user | Yes | All run on O2 network; G100 boosts their calls |
| Lebara / Lycamobile user | Yes | Run on Vodafone/O2; G100 compatible |
| Elderly user who only needs calls | Yes | Simple install, no app, no data needed |
| Small flat / bedsit with poor signal | Yes | 100 m² covers most small flats; cheap to fix |
| EE or Three user | No — choose C100 | G100 does not support EE/Three voice frequencies |
| User needing 4G/5G data | No — choose C100 | G100 is calls/SMS only; C100 boosts 4G data |
| Family home 200+ m² | No — choose C300 | 100 m² will only cover one room |
| User with zero outdoor signal | No | Booster needs at least 1 bar; contact network operator |
Troubleshooting Common G100 Issues
Issue 1: Signal LED red or flashing
Red/flashing LED means oscillation (feedback between antennas). Move the indoor antenna at least 5 m from the outdoor antenna and ensure they are not in direct line of sight. The G100's AGC reduces gain automatically, but a red light means separation is insufficient.
Issue 2: No improvement in call quality
Check three things: (1) Is the outdoor antenna pointing at the nearest mast? (2) Are cable connections tight? (3) Is there at least 1 bar of 900 MHz signal outdoors? Also verify you are on O2 or Vodafone — the G100 does not work with EE or Three.
Issue 3: Signal good near booster, weak further away
Normal for a 100 m² booster. The G100 covers one room or a small flat. For larger spaces, upgrade to the C300 (300 m²) or add the 2-way splitter and second indoor antenna.
Issue 4: Booster feels warm
The aluminium housing acts as a heatsink and will feel warm (35–40 °C) during normal operation. This is expected and safe. Ensure at least 10 cm ventilation space around the unit.
Real User Experiences
We analysed 35+ verified UK customer reviews of the G100. Key findings:
- 83% rated it 4 or 5 stars. Most common praise: "finally can make calls indoors" and "so cheap and easy."
- Average reported improvement: from 0–1 bar to 4–5 bars for calls.
- Most common complaint: "wish it did 4G data too" and standard delivery time.
- Network breakdown: 35% O2, 28% Vodafone, 18% giffgaff, 10% Sky Mobile, 9% other MVNOs. All reported successful call boosting.
- Return rate: approximately 5%, primarily from EE/Three users who bought the wrong booster.
G100 vs G100 Alternatives: Detailed Breakdown
Boost4U G100 vs Boost4U C100: Which Should You Buy?
The G100 and C100 are both single-band boosters from the same manufacturer, but they serve different purposes. The G100 (£75) amplifies Band 8 (900 MHz) for 2G/3G voice calls and SMS on O2/Vodafone networks. The C100 (£109.99) amplifies Band 20 (800 MHz) for 4G LTE data and VoLTE calls on all four UK networks. The key difference is that the G100 improves traditional circuit-switched calls, while the C100 improves packet-switched 4G data and VoLTE. If your phone is set to "prefer 2G/3G for calls" or your area has poor VoLTE coverage, the G100 is the more reliable choice for call quality. If you primarily use VoLTE and need faster data, the C100 is better. Many users install both for complete redundancy.
Boost4U G100 vs weBoost Home Room: Value Comparison
The weBoost Home Room (£349) is a multi-band booster supporting 3G and 4G bands 3, 7 and 20. On paper it is more versatile, but for O2/Vodafone voice calls specifically, it does not support Band 8 (900 MHz) — the primary voice frequency for those networks. This means for traditional 2G/3G calls on O2/Vodafone, the weBoost actually performs worse than the G100, despite costing 4.7x more. The weBoost only outperforms the G100 if you need multi-band 4G data support across multiple frequencies. For pure call quality on O2/Vodafone, the G100 is the better and far cheaper choice.
Final Verdict
The Boost4U G100 is the best budget call signal booster under £80 in the UK in 2025. It is not the most feature-rich or powerful booster, but it does the one thing that millions of O2 and Vodafone users actually need — make reliable phone calls and send texts from home — and it does it for £75 with a 365-day safety net.
For O2, Vodafone, giffgaff, Sky Mobile, Tesco Mobile, Lebara and Lycamobile users who are frustrated by dropped calls and unsent texts in a small home or flat, the G100 is a no-brainer. It costs less than many monthly phone contracts, installs in 11 minutes, and transforms a frustrating 0–1 bar experience into a reliable 4–5 bar connection for calls.
The only reasons to look elsewhere are: you need 4G/5G data (buy the C100), you are on EE or Three (buy the C100), you need more than 100 m² coverage (buy the C300), or you have zero outdoor signal (contact your network operator). For everyone else in the O2/Vodafone ecosystem, the G100 is the highest-value call booster in the UK.
Rating: 4.5 / 5.0 — Editor's Choice for Best Budget Call Signal Booster UK 2025.
Buy the Boost4U G100 for £75.00 with free UK shipping and 365-day returns →
Frequently Asked Questions
1. Is the Boost4U G100 any good?
Yes. In our 30-day test, the G100 lifted O2 indoor call signal from 1 bar (-110 dBm) to 5 bars (-80 dBm), reduced dropped calls from 18% to 2%, and improved SMS delivery from 72% to 100%. It earned a 4.5/5 rating and our Editor's Choice for best budget call booster.
2. How much does the Boost4U G100 cost?
The G100 is priced at £75.00 GBP, reduced from £95.00 (21% saving). This includes free UK standard shipping (10–15 business days) and a 365-day money-back guarantee. Optional upgrades include a 15 m cable (£30.99), high-gain antenna and surge protector.
3. Does the G100 boost 4G or 5G data?
No. The G100 is a Band 8 (900 MHz) booster for voice calls and SMS only. It does not amplify 4G LTE or 5G data frequencies. If you need mobile internet, choose the Boost4U C100 4G LTE booster (£109.99). Many users install both — G100 for calls, C100 for data.
4. Which networks does the G100 support?
The G100 supports O2 and Vodafone and all their MVNOs: giffgaff, Sky Mobile, Tesco Mobile, Lebara and Lycamobile. This is because all these networks use Band 8 (900 MHz) for voice calls. It does NOT work with EE or Three, which use different voice frequencies.
5. Is the G100 legal in the UK?
Yes. The G100 is UKCA / CE certified and meets Ofcom's licence-exempt mobile repeater technical standard, including the 17 dBm maximum output power limit, proper band-pass filtering and Automatic Gain Control. It can be legally installed and operated without a licence.
6. How long does installation take?
Most users install the G100 in 10–15 minutes. Our timed installation took 11 minutes 20 seconds. No tools are required for a basic window-mount installation. Roof mounting may require a drill and the 15 m cable upgrade.
7. What if the G100 does not work in my home?
Boost4U offers a 365-day money-back guarantee. If the G100 does not improve your signal, return it within 365 days for a full refund. The most common reason for failure is having zero outdoor signal or being on EE/Three (which the G100 does not support).
8. Can multiple people use the boosted signal at once?
Yes. The G100 supports unlimited simultaneous users and devices with no per-device cap. The whole household can make calls and send texts simultaneously. Call quality depends on the available mast capacity, not the booster.
9. How does the G100 compare to the C100?
The G100 (£75) is a Band 8 call/SMS booster for O2/Vodafone only. The C100 (£109.99) is a Band 20 4G LTE booster for all four networks that also handles data and VoLTE calls. The G100 is £34.99 cheaper but does not improve data. Choose based on whether you need calls only (G100) or calls + data (C100).
10. How many square metres does the G100 cover?
The G100 covers up to 100 m² (approximately 1,076 ft²), typically one large room or a small flat. Actual coverage depends on outdoor signal strength and building materials. In our stone cottage test, usable 3+ bar coverage was approximately 75 m². For larger homes, consider the C300 (300 m²).
