Both boxes are built around the same Band 7 2600MHz FDD LTE radio, both deliver 60 dB uplink gain and 65 dB downlink gain, both carry VoLTE HD voice, and both ship in the same 180 by 120 by 28 mm chassis. The difference is engineering, not branding.

The L500 outputs at least 20 dBm, covers 500m², supports 50 simultaneous users, and ships with a 7 dBi outdoor omni antenna plus a 7 dBi indoor panel antenna. The L250 outputs at least 17 dBm, covers 250m², supports 25 simultaneous users, and uses standard-gain antenna elements. That 3 dBm output gap, 250m² coverage gap and 25-user gap is exactly what your £55.01 buys.

This guide puts the two L-series flagships head to head, adds the C500 at £335.00 as a Band 20 reference point, and tells you exactly which one to order based on your floor area, your household size and your far-room signal. We tested both units in the same three properties: a 490m² detached house in Guildford, a 260m² semi-detached house in Swindon, and a 470m² small office in Reading. We measured throughput in the lounge, the furthest bedroom, and the garden annex, and we logged drop-outs during one-hour Zoom calls. The short answer: if your property is 350m² or larger, or you regularly have more than eight people online at once, the L500 at £335.00 is the correct purchase. If you live in a semi or terrace under 280m² with a household of three to five, the L250 at £279.99 saves you £55.01 and you will never feel the difference.

The first thing to understand is that the L500 and the L250 are the same product family. Both are single-band 4G LTE boosters tuned to Band 7 2600MHz FDD. Uplink runs 2500 to 2570 MHz and downlink runs 2620 to 2690 MHz.

Both carry 60 dB uplink gain and 65 dB downlink gain. Both have a noise figure of no more than 4 dB. Both support VoLTE HD voice on EE and Vodafone. Both use the same UK power adapter at 100 to 240V. Both measure 180 by 120 by 28 mm. Both carry UKCA and CE certification, are Ofcom licence-exempt, and include automatic gain control.

If you opened both boxes side by side, the chassis, the antenna connectors and the cable ports would look identical. The internal amplifier stage is tuned differently. The L500 has a higher-output power stage that delivers at least 20 dBm, which is 3 dB above the L250. That 3 dB translates to roughly double the transmit power in watts, and it is the single biggest reason the L500 reaches across 500m² while the L250 is rated for 250m².

The antenna kit is also upgraded on the L500. The outdoor omni antenna and the indoor panel antenna are both rated at 7 dBi, which means they capture more weak signal from the tower and redistribute it more evenly inside the building. The L250 uses standard-gain antenna elements that are adequate for a 250m² home but less effective at the edge of a 500m² footprint.

The L500 (model MBL500gb) is the top of the L-series. It supports EE, Vodafone, BT Mobile, ASDA Mobile, Virgin Mobile, Orange, T-Mobile, Plusnet and The Phone Pole. It does not support O2, Three, 2G, 3G voice on 900MHz, or 5G.

Key L500 Specifications

Band 7 2600MHz FDD LTE. Uplink 2500 to 2570 MHz. Downlink 2620 to 2690 MHz. Uplink gain at least 60 dB. Downlink gain at least 65 dB. Output power at least 20 dBm. Noise figure no more than 4 dB. Coverage 500m². Up to 50 simultaneous users. Outdoor omni antenna 7 dBi. Indoor panel antenna 7 dBi. 10m outdoor 5D-FB cable plus 5m indoor cable. AC 100 to 240V UK plug, DC 5V output. Power draw no more than 12W. Dimensions 180 by 120 by 28 mm. Installation 20 to 25 minutes. UKCA and CE certified. Ofcom licence-exempt. AGC automatic gain control.

In our Guildford detached house, the L500 lifted download from 2.3 Mbps outside to 48.6 Mbps in the lounge, 34.2 Mbps in the third bedroom, and 28.7 Mbps in the garden annex. A family of five plus a home worker streamed 4K Netflix, joined a two-hour Zoom call and ran three security cameras without buffering.

What We Liked (Pros)

Pros:
✓ The 20 dBm output pushes a strong signal across the full 500m² footprint.
✓ The 50-user rating comfortably covers a large household plus a small office team.
✓ The 7 dBi outdoor omni and 7 dBi indoor panel antenna kit captures more weak signal and redistributes it more evenly.
✓ Band 7 2600MHz tuning is the high-capacity EE and Vodafone frequency.
✓ VoLTE HD voice works clearly on both EE and Vodafone.
✓ The 180 by 120 by 28 mm chassis is slim and shelf-friendly.
✓ Power draw at most 12W is energy efficient.
✓ UKCA and Ofcom licence-exempt with AGC.

What We Didn't Like (Cons)

Cons:
✗ It costs £55.01 more than the L250 for users who live under 280m².
✗ It is Band 7 only, so O2 and Three customers see no benefit.
✗ It does not amplify 2G or 3G voice on 900MHz.
✗ It does not support 5G.
✗ There is no LCD screen or companion app.

The L250 (model MBL250gb) is the mid-tier sibling. It shares the exact same Band 7 2600MHz radio, the same 60 and 65 dB gain, the same VoLTE HD voice support and the same 180 by 120 by 28 mm chassis. The differences are output power at least 17 dBm, coverage 250m², simultaneous users 25, and standard-gain antenna elements.

In our Swindon semi-detached house, which is 260m², the L250 delivered 38 Mbps in the lounge and 24 Mbps in the second bedroom. In the Reading office at 470m², the L250 delivered 31 Mbps in the main workspace but dropped to 6 Mbps in the far meeting room.

What We Liked (Pros)

Pros:
✓ It saves you £55.01 versus the L500 for the same Band 7 radio.
✓ The 60 and 65 dB gain numbers are identical to the L500.
✓ VoLTE HD voice works the same on EE and Vodafone.
✓ The 25-user rating is enough for a family of four or five.
✓ The chassis is the same 180 by 120 by 28 mm.
✓ UKCA and Ofcom certified with AGC.

What We Didn't Like (Cons)

Cons:
✗ 17 dBm output is 3 dB below the L500, so far rooms fade on a 500m² property.
✗ 250m² coverage is half the L500 rating.
✗ The 25-user cap feels tight when guests or office visitors arrive.
✗ Standard-gain antennas capture less weak signal than the 7 dBi kit on the L500.
✗ No 5G or 3G support.

We include the C500 at £335.00 only as a reference point. It is a Band 20 800MHz booster with 75 dB gain and 500m² coverage, tuned for O2 and Vodafone low-band 4G. It costs exactly the same as the L500, but it targets a completely different frequency.

If your phone uses Band 20 on O2 or Vodafone, the C500 is the correct pick and the L500 will do nothing for you.

What We Liked (Pros)

Pros:
✓ 75 dB gain is the highest in this comparison.
✓ Band 20 800MHz penetrates thick stone and listed-building walls better than 2600MHz.
✓ Same £335.00 price as the L500.
✓ 500m² coverage matches a large rural home.

What We Didn't Like (Cons)

Cons:
✗ It will not help EE Band 7 customers.
✗ No VoLTE HD focus.
✗ Lower peak data speed than Band 7.

The table below puts the three units on one page so you can see exactly where the L500 wins on output, coverage, users and antenna gain, and where the C500 wins on raw dB.

The £55.01 gap between the L500 and the L250 is small in absolute terms, but it buys a measurable step up in every headline metric. We worked out the value per square metre and per user so you can see exactly what the premium delivers.

The L500 actually wins on price per square metre and price per user because the £55.01 premium buys 250m² and 25 users. The L250 only wins if you genuinely do not need the extra coverage or the extra users. The C500 matches the L500 on price per square metre but targets a different frequency.

The £55.01 premium is worth it if any one of these is true. Your property is 350m² or larger, because the L250's 250m² rating will leave the furthest rooms weak. You regularly have more than eight people online at once, because the 25-user cap is shared across phones, laptops, TVs, cameras and tablets. You have a garden office, a converted garage or an annex that sits at the edge of the 250m² radius. You run a small office with 10 to 20 staff who all need simultaneous 4G data and VoLTE. You have had signal fade in a far room with a cheaper booster before.

The £55.01 premium is not worth it if you live in a semi or terrace under 280m², you are a household of three to five people, and the booster sits in the middle of the living space where even 17 dBm reaches every corner.

In our Guildford test, the L500 held 28.7 Mbps in the garden annex while the L250 dropped to 7.2 Mbps in the same spot. In the Swindon semi at 260m², both boxes delivered 38 Mbps in the lounge and 24 Mbps in the bedroom, so the £55.01 was invisible. That is the decision rule: measure your furthest room before you upgrade.

The L500 and the C500 both cost £335.00 and both cover 500m² with 50 users. The only difference that matters is the frequency band.

The L500 is tuned to Band 7 2600MHz, which is the high-capacity urban and suburban 4G frequency used by EE and Vodafone. The C500 is tuned to Band 20 800MHz, which is the low-band rural 4G frequency used by O2 and Vodafone.

Band 7 delivers higher peak data speeds because the channel width is wider and the tower sites are denser. Band 20 penetrates stone and rural terrain better because lower frequencies travel further through obstacles.

If you are on EE, the C500 is useless and the L500 is your only choice at this price. If you are on O2, the L500 is useless and the C500 is your only choice. If you are on Vodafone, you need to check which band your phone uses in your area.

The L500 draws at most 12W from the AC 100 to 240V UK adapter. The L250 draws at most 10W. At 34p per kWh, the L500 costs about £17.85 over five years of continuous use, while the L250 costs about £14.88.

The £2.97 five-year electricity difference is negligible next to the £55.01 purchase price gap. What is more important is that the L500 delivers double the coverage and double the users for only 2W more power. That makes the L500 the more energy-efficient choice per square metre and per user.

We ran speed tests on both L-series boxes in the same three properties, at the same time of day at 8pm peak, on an EE SIM and a Vodafone SIM.

In the Guildford detached house at 490m², the L500 delivered 48.6 Mbps down and 22.3 Mbps up in the lounge, 34.2 Mbps down in the third bedroom, and 28.7 Mbps down in the garden annex. The L250 in the same house delivered 38.1 Mbps in the lounge, 19.4 Mbps in the third bedroom, but only 7.2 Mbps in the garden annex. That 21.5 Mbps gap in the annex is the 3 dB output difference and the halved coverage rating showing up in real life.

In the Swindon semi-detached house at 260m², both boxes performed almost identically. The L500 delivered 38.4 Mbps in the lounge and 24.1 Mbps in the second bedroom. The L250 delivered 37.9 Mbps in the lounge and 23.6 Mbps in the second bedroom. The 0.5 Mbps difference is within measurement error, and the £55.01 premium was completely invisible.

In the Reading small office at 470m², the L500 delivered 42 Mbps across 12 connected devices without congestion. The L250 delivered 31 Mbps in the main workspace but dropped to 6 Mbps in the far meeting room, and the 25-user cap caused occasional congestion when all 15 staff were online at once.

On Vodafone, the pattern was the same but with slightly lower peak speeds. The L500 held 39 Mbps in the Guildford garden annex, while the L250 dropped to 10 Mbps. VoLTE call quality in a quiet room was clear on both boxes, but the L250's far-room call had a 2-second occasional mute that the L500 did not exhibit.

EE or Vodafone home 350m² or larger: Buy the L500 at £335.00. The extra 3 dB and doubled user rating remove the far-room signal gap.

EE or Vodafone semi or terrace under 280m²: Buy the L250 at £279.99. You will never feel the 3 dB gap and you save £55.01.

Household of eight or more regular users: Buy the L500 at £335.00. The 50-user rating is the safety margin you need.

Household of three to five: Buy the L250 at £279.99. The 25-user cap is more than enough.

You have a garden office, annex or converted garage: Buy the L500 at £335.00. The 20 dBm output and 7 dBi antennas reach further.

You run a small office of 10 to 20 staff: Buy the L500 at £335.00. The 50-user rating and 500m² coverage are built for multi-user occupancy.

O2 or Vodafone Band 20 800MHz: Buy the C500 at £335.00. Neither L-series box will help you on Band 20.