Step one: test on Ethernet
Connect a laptop directly to your router or ONT with a cable, disable VPNs, and run multiple speed tests to UK servers at different times of day. If wired speeds match your guarantee but Wi-Fi crawls, optimise placement or upgrade wireless gear—see our Wi-Fi and router placement guides.
Step two: rule out local overload
Heavy uploads—cloud backups, CCTV uploading, torrent seeding—can saturate uplink and make latency spike for everyone else. Quality-of-service settings on advanced routers help; some ISP hubs are basic, so schedule big uploads overnight.
Step three: FTTC distance and noise
On part-fibre, your sync speed is physics-limited by copper length. Sudden drops may mean line faults or electrical noise—your provider can run remote diagnostics and book Openreach if needed. Intermittent REIN interference from faulty streetlights or transformers is harder but real.
Step four: provider and backhaul
If wired tests are poor at all hours, raise a fault. Beyond the local loop, core congestion is rarer on major ISPs but spikes during big sporting streams or regional outages—check status pages and Downdetector with salt. Automatic compensation may apply for prolonged total loss on qualifying products.
If your line technology is simply outdated, SwitcherMate can show whether FTTP or cable now overlaps your postcode so you upgrade instead of chasing copper margins.
Micro-outages and credit for downtime
Brief drops may not show on coarse speed tests but will kill VPN tunnels. Router logs—if accessible—often show PPP session resets or DHCP renewals at the same times you noticed crashes. Pair this evidence with traceroutes when filing faults.
Automatic compensation on qualifying fixed products is not automatic charity—you still need to report outages to start clocks. Keep a simple diary linked to your ticket numbers.