Internet downtime isn’t just inconvenient these days; it can be costly. Whether you’re processing transactions, running VoIP calls, hosting cloud systems or serving customers online, reliable internet is non-negotiable, so more UK businesses are pairing leased lines with 4G or 5G backup connections to create a fail-safe network.
Join us as we explain how to set up a leased line with backup that UK businesses can trust, explore the benefits of failover internet for business, and compare top UK providers offering resilient connectivity.
What Is Internet Failover?
Failover internet is a secondary connection that activates automatically if your primary link goes down and in most cases, businesses use:
- A leased line as the primary connection (dedicated fibre)
- A 4G or 5G router as a backup
This ensures continuity during:
- ISP outages
- Fibre cuts or cable damage
- Hardware failures
- Planned maintenance or upgrades
Why Combine a Leased Line with 4G/5G Failover?
1. Minimise your downtime risk
Downtime costs UK SMEs thousands in lost revenue and productivity. Failover protects against:
- Missed customer calls or online orders
- Payment terminal failures
- CRM or EPOS outages
2. Support business continuity planning
Whether you’re managing hybrid teams or running cloud-based services, failover ensures operations never stop.
3. Comply with industry standards
Regulated industries (finance, healthcare, legal) often require redundancy for data compliance and uptime.
4. Cost-effective resilience
Unlike a second leased line, 4G/5G backup is low-cost, quick to deploy, and fast enough for critical workloads.
How Does Leased Line Failover Work?
Component | Role |
Primary Leased Line | Delivers high-speed, symmetrical, uncontended internet |
Failover 4G/5G Router | Monitors line health and switches over during outage |
Firewall or Load Balancer | Manages automatic switching and reconnection |
Static IP Configuration | Ensures seamless failover for services and VPN access |
Failover routers detect disruptions and automatically switch traffic to the backup connection, often within seconds. When the leased line is restored, the system switches back.
Features of an Effective Business Failover Setup
- Automatic failover switching
- Dual SIM support for multi-network redundancy (e.g. Vodafone + EE)
- QoS and traffic shaping to prioritise essential traffic during failover
- Static IP on both links (if needed for VPN or hosted systems)
- Centralised monitoring (via SD-WAN or managed network services)
Leased Line with 4G/5G Backup: UK Providers
| Provider | Backup Option Included | Router Provided ? | From |
| Optional 4G/5G failover | Yes | £399 + £10-£20 |
| Integrated 4G failover | Yes | £400 + £15+ |
| 4G backup available | Yes | £450 + £20 |
| Optional 4G failover | Yes | £375 + £15 |
| 4G included as standard | Yes | £399+ |
Choosing the Right Failover Hardware
Some of the most common 4G/5G failover routers for UK business use:
- DrayTek Vigour 2865Lac: Dual SIM, built-in firewall, VPN-ready
- TP-Link ER605 + LTE modem: Budget-friendly, ideal for small sites
- Ubiquiti UniFi LTE Pro: Plug-and-play LTE backup for UniFi networks
- Cisco Meraki MX68CW: Enterprise-grade SD-WAN and failover
Ensure the device supports:
- Dual WAN with automatic failover
- External antenna support (for weak signal areas)
- Cloud-based monitoring (for managed services)
FAQs
Q: Can 4G/5G failover support full operations during an outage?
A: For most SMEs, yes. While not as fast as fibre, 4G/5G can handle payments, VoIP, email, and cloud access in the short term.
Q: Will I need a second static IP address?
A: Only if your business services rely on fixed IPs. Many providers offer failover-compatible static IP ranges.
Q: Is SD-WAN required for failover?
A: Not always. Basic dual-WAN failover works fine, but SD-WAN offers improved traffic management, analytics, and security.
Final Thoughts About 4G and 5G Failover
we think there’s no doubt that a leased line offers incredible speed and reliability, but even the best infrastructure can experience unexpected issues. That’s why adding a failover internet for businesses using 4G or 5G is one of the most cost-effective steps to protect uptime.
