Why Is My Broadband So Slow? (2026)

Slow broadband is most commonly caused by Wi-Fi interference, too many devices sharing the connection, peak-time network congestion between 7pm and 11pm, an outdated router, or a fault on your line. Run a speed test over Ethernet to isolate the issue — if wired speeds are fine, the problem is your Wi-Fi setup rather than your broadband connection itself.

Common Causes of Slow Broadband

Ofcom research shows 43% of broadband speed complaints are actually Wi-Fi problems, not line issues. Thick walls, distance from the router, interference from baby monitors and microwaves, and congested Wi-Fi channels all degrade speeds. Beyond Wi-Fi, older copper ADSL lines physically cannot deliver modern speeds — the maximum is around 11 Mbps regardless of your plan. FTTC connections lose speed with distance from the street cabinet, dropping from 80 Mbps at 100 metres to 30 Mbps at 500 metres. Peak-time congestion between 7pm and 11pm affects over-subscribed networks. Even your router's age matters: a five-year-old Wi-Fi 4 router cannot exploit the speeds a BT Full Fibre 900 plan delivers. Hardware faults, damaged cables and exchange-level issues account for the remainder of slow speed cases.

How to Diagnose the Problem

Start with a wired Ethernet speed test to establish your actual line speed. If wired speeds match your plan's minimum guaranteed speed but Wi-Fi is slow, the issue is within your home. If wired speeds are also below par, the problem lies with your connection or provider. Run tests at three different times of day to check for peak-time drops. Sky Broadband customers can use the Sky Broadband Buddy app for diagnostics, and Virgin Media's Connect app shows real-time speeds per device. Check your router's admin panel for error logs and connected device counts — most households now have 15-20 connected devices, each consuming some bandwidth. If you are on FTTC and live far from your cabinet, there may simply be a physical limit to your attainable speed, making a switch to FTTP the only real solution.

Quick Fixes You Can Try Right Now

Restart your router by switching it off for 30 seconds, then back on — this clears temporary errors and can re-establish a faster connection profile. Move the router away from walls, the floor and electronic devices. Switch to the 5GHz Wi-Fi band for devices in the same room. Update your router's firmware through its admin panel. Disconnect devices you are not using, especially those running automatic cloud backups. If your Vodafone router shows congestion on its current channel, its Smart Wi-Fi feature automatically switches to a less crowded one. Powerline adapters let you extend wired connections to distant rooms without running visible cables. For Plusnet customers, the Hub One router supports both 2.4GHz and 5GHz — make sure you are connected to the faster 5GHz network from your main devices.

When to Complain or Switch Provider

If your speeds consistently fall below the minimum guaranteed speed in your contract after trying all fixes, contact your provider's support team. Under Ofcom rules, they must resolve the issue within 30 days or let you leave penalty-free. Keep speed test screenshots with dates and times as evidence. Automatic Compensation rules mean you are owed £6.10 per day for delayed repairs if your provider has signed up to the scheme. If your provider cannot fix the problem, consider switching. The One Touch Switch process takes just one working day and has handled over 1.6 million switches since launch. Check whether Hyperoptic, Community Fibre or another altnet serves your area — their newer networks often deliver faster, more consistent speeds than older infrastructure. EE Full Fibre and BT Full Fibre plans run on the Openreach FTTP network covering 82% of UK premises.

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Frequently Asked Questions

Why is my broadband slow only in the evenings?

Evening congestion between 7pm and 11pm occurs when most people stream, game and browse simultaneously. Over-subscribed networks slow down during these hours. FTTP full fibre connections handle peak times better than copper-based ADSL or FTTC. Switching to a less congested provider or upgrading to fibre often solves this.

Can my neighbours' broadband usage affect my speed?

On shared networks like Virgin Media's cable infrastructure, heavy local usage can reduce speeds during peak hours. ADSL connections share capacity at the exchange level. FTTP full fibre gives you a dedicated line to the exchange, so neighbours' usage has minimal impact on your speed.

Should I replace my router to fix slow broadband?

If your router is more than three years old, a newer Wi-Fi 6 model can significantly improve wireless speeds. Contact your provider first — many offer free router upgrades. However, a new router will not increase your line speed, only the Wi-Fi performance within your home.

How do I get compensation for slow broadband?

If your provider is part of Ofcom's Automatic Compensation scheme, you receive £6.10 per day for delayed repairs beyond two working days. Contact your provider, log a fault and keep records. After eight weeks without resolution, escalate to Ombudsman Services or CISAS.

Related Guides

How to Improve Broadband Speed · Broadband Speed Test Guide · Broadband Complaints and Your Rights · What Is a Good Broadband Speed

Methodology & Sources

Information in this guide is sourced from Ofcom market reports, Openreach coverage data, ISPreview.co.uk, provider websites and independent broadband research from Point Topic and Thinkbroadband. Prices and availability are checked monthly. Speed data reflects advertised average speeds from provider Key Facts documents.