Independent UK guides · checked 13 November 2026
Stay online when your broadband doesn't.
Plain-English guides to broadband backup in the UK: 4G and 5G failover, provider add-ons, satellite, power cuts and the 2027 landline switch-off. Sourced, dated and free of sales pitches.
Illustration, not a live status. Real switch-over takes from seconds to a few minutes.
The rule that matters
A backup only helps if it does not share the failure
A mobile backup covers line faults and provider outages, but not a power cut unless your router is on a battery. Pick an option to see which of the five common failures it survives.
- Covered
- Covered, with a condition
- Only with extra kit
- Depends
Phone hotspot
- Switch-over
- Manual
- Indicative cost
- No extra cost; uses your mobile data
- Fault on your lineCoveredYes
- Provider-wide outageCoveredYes
- Your router failsCoveredYes
- Power cut at your home onlyCovered, with a conditionYes, while the phone has charge
- Wide-area power cutDependsDepends on whether the mast stays powered
Mobile backup
- Switch-over
- Automatic
- Indicative cost
- Provider add-on (EE: £10 a month) or your own 4G/5G router from about £89 plus a SIM
- Fault on your lineCoveredYes
- Provider-wide outageCoveredYes
- Your router failsOnly with extra kitOnly if the backup has its own router or Wi-Fi
- Power cut at your home onlyOnly with extra kitOnly with a battery for your equipment
- Wide-area power cutDependsDepends on the mast, and needs a battery at home
Second fixed line
- Switch-over
- Automatic
- Indicative cost
- The price of a second broadband package
- Fault on your lineCovered, with a conditionYes, if it uses a different physical network
- Provider-wide outageCovered, with a conditionYes, if it is a different provider and network
- Your router failsOnly with extra kitOnly with a separate router
- Power cut at your home onlyOnly with extra kitOnly with a battery
- Wide-area power cutDependsDepends on street cabinets, and needs a battery
Satellite
- Switch-over
- Depends on setup
- Indicative cost
- Starlink residential plans from £40 a month; Standby Mode £9 a month
- Fault on your lineCoveredYes
- Provider-wide outageCoveredYes
- Your router failsCoveredYes, it has its own router
- Power cut at your home onlyOnly with extra kitOnly with a battery
- Wide-area power cutOnly with extra kitNeeds a battery at home; does not rely on local masts
From the table in the complete guide. Prices checked November 2026.
Five in-depth guides
From "do I need one?" to a tested setup
Each guide has comparison tables, worked costs, answers to common questions and a numbered list of every source it relies on.
- 15 min read Start here Broadband Backup in the UK: The Complete Guide to Staying Online Why connections fail, what Ofcom compensation really pays, the ways to build a backup, what they cost and a five-question test for whether you need one. Read the guide
- 14 min read Mobile backup 4G and 5G Backup Broadband: How It Works, What to Buy and What It Costs Routers, SIMs and data plans, how to check indoor signal, how much data a backup really uses and three worked two-year costs. Read the guide
- 15 min read For small firms Business Broadband Backup: Failover, Dual-WAN and SLAs for Small Firms What an hour offline costs, why compensation will not cover you, repair levels, dual-WAN, and keeping phones and card payments working. Read the guide
- 16 min read Step by step How to Set Up Automatic Broadband Failover at Home, Step by Step Three routes to automatic failover, the detection settings that matter, a pull-the-plug test drill, batteries and troubleshooting. Read the guide
- 14 min read Compare options ISP Backup vs DIY vs Satellite: Which Broadband Backup Suits You? Provider add-ons brand by brand, the true two-year cost of DIY, Starlink Standby, six household verdicts and the contract traps. Read the guide
Key numbers
Six figures worth knowing before you spend anything
Checked on 13 November 2026. Each one links to the guide that explains the detail, the exceptions and the source.
- Ofcom automatic compensation £10.34 a day Paid only once a total loss of service has lasted beyond two full working days. Residential services only.
- Analogue landline switch-off 31 Jan 2027 The analogue phone network is retired by 31 January 2027. Digital landlines run over broadband and need mains power.
- 4G reach, per operator 99% of premises Each UK operator's 4G network reaches at least 99% of premises outdoors, so most homes have a usable network.
- A provider 4G add-on £10 a month EE charges £10 a month for its Connectivity Backup add-on. Most providers sell no household backup at all.
- DIY 4G failover router £89 and up A 4G router with a failover port costs from about £89, plus a data SIM. Works with any broadband provider.
- Emergency calls in a power cut 1 hour minimum If you depend on your landline, your provider must give you a way to call 999 in a power cut lasting at least one hour.
Do you need a backup?
A five-question check
Work through these in order and stop when the answer is clear. Plenty of households need no paid backup at all.
What does an hour offline cost you?
If the honest answer is very little, you do not need to spend money.
How often are you offline, and for how long?
Look at your own record and your router's log, not national surveys.
Is your phone enough?
Check signal, data allowance and tethering at your desk. If all three are good, a hotspot is a legitimate backup.
Is power the real problem?
If outages coincide with power cuts, solve power first: a battery for the fibre box and router.
Does anything need to stay online when you are not there?
Cameras, heating, a card machine, someone working upstairs: this is where automatic failover earns its keep.
How the guides are made
Sourced, dated, independent
- Primary sources first: Ofcom, Openreach and the providers' own published terms and price guides.
- Every figure carries a numbered source, and each guide shows when its facts were last checked.
- No hands-on testing is claimed. Worked costs are labelled as illustrations built from published prices.
- No provider pays to appear here. No ads, affiliate links, sponsored content or tracking.
Already decided?
The setup guide walks through three routes to automatic failover, the detection settings that matter and a pull-the-plug drill to prove it works before you need it.