Fuse Mobile launch: one eSIM across all four UK networks

Last reviewed: 10 July 2026

What Fuse Mobile has launched

Fuse Mobile went live on 1 July 2026 as a virtual operator built entirely around eSIM technology. The proposition is unusual in the UK market: rather than reselling capacity on a single host network as conventional virtual operators do, its plans can connect to the 4G and 5G networks of all four national operators, EE, Three, Vodafone and O2, and the connection switches automatically to whichever network has the strongest signal at the user's location. The launch lineup is three rolling monthly plans: Spark at £5.99 for 5GB, Pulse at £9.99 for 10GB and Surge at £14.99 for 15GB. On Pulse and Surge the same allowance also functions in more than 130 countries with no additional roaming charge; Spark is UK only. The product is data only: there is no phone number, no carrier voice and no SMS, so it is designed to sit alongside an existing SIM as a second line, with tethering supported on all plans and a 7 day free trial before the first charge on day 8.

The problem the product addresses

UK mobile coverage is strong in aggregate and uneven in detail. Ofcom data cited by the provider puts around 17% of the UK without reliable 4G from any single network, and each network's weak spots sit in different places, which is why coverage maps disagree and why a phone that works in one village drops out in the next. A single plan that roams across all four networks addresses precisely that gap pattern, in the way that emergency calls already do. The nearest existing comparisons are Honest Mobile's Smart SIM, a multi network backup eSIM restricted to a list of approved apps, and the multi network SIMs long used in payment terminals; Fuse packages the idea for consumers with unrestricted data. One caveat belongs on the record: early independent testing reported connections only to Three and O2 in some locations, so whether all four networks are reachable in practice everywhere is a claim the product will have to prove in use.

How it compares on price per gigabyte

Against mainstream single network SIMs the comparison is lopsided in both directions. Budget virtual operators price aggressively on volume: spusu offers 10GB for £6.90 and 20GB for £7.90 on EE's network, roughly 40p per gigabyte against Pulse's £1 per gigabyte, and CommunityFibre's new eSIM offers unlimited 5G data at £15 per month for its broadband customers. Fuse cannot compete with those figures on price per gigabyte and its positioning suggests it does not intend to: the value is measured in coverage continuity rather than volume, and the absence of a phone number makes it structurally a second line. A user whose primary SIM costs £7 to £15 per month can add Spark at £5.99 as insurance against dead zones. On that framing the relevant comparison is not price per gigabyte but the cost of connectivity failing at the wrong moment, which is a personal number rather than a market one.

The roaming dimension

The 130 plus country roaming allowance on the Pulse and Surge plans lands in a market where roaming charges have quietly returned. EE, Vodafone and Three all reintroduced daily EU roaming fees after 2022, typically around £2 to £3 per day, while O2 kept EU roaming inclusive. A traveller taking a two week European trip on a network with daily charges faces £28 to £42 of roaming fees; a data allowance that simply works abroad removes that line item. Travel eSIM specialists such as Airalo and Holafly compete in the same space with country specific bundles, so the comparison for travellers is between a permanent UK plan with roaming included and a disposable bundle purchased per trip.

What is worth watching

Multi network switching depends on the commercial and technical arrangements underneath, and the mechanism the industry watches is whether switching is seamless mid session or occurs on reconnection. Early user reports since the 1 July launch note the modest allowances as the main limitation, consistent with a backup role. The pricing of the Pulse and Surge tiers against their allowances, and whether an unlimited or high allowance tier follows, will determine whether the product graduates from resilience layer to primary SIM candidate. The launch itself is recorded on the product launch tracker with the plan lineup as published at launch.

Frequently asked questions

What is Fuse Mobile?

A UK virtual mobile provider launched on 1 July 2026, selling data only eSIM plans that connect automatically to whichever of the four national networks, EE, Three, Vodafone or O2, has the strongest signal.

How much do Fuse Mobile plans cost?

Spark is £5.99 a month for 5GB, Pulse is £9.99 for 10GB and Surge is £14.99 for 15GB. All are rolling monthly with no contract, and a 7 day free trial applies before the first charge.

Does Fuse Mobile include calls and texts?

No. The service is data only, with no phone number, carrier calls or SMS. It is designed to run alongside an existing SIM, which keeps handling calls and texts on the current number.

Does Fuse Mobile work abroad?

On the Pulse and Surge plans the data allowance works in more than 130 countries at no extra cost. The Spark plan is UK only.

Is Fuse Mobile cheaper than a normal SIM?

Not on price per gigabyte. Budget operators such as spusu sell 20GB for £7.90 on a single network, roughly 40p per gigabyte against Pulse's £1. Fuse's case is coverage continuity across all four networks rather than data volume.