Slow Wi-Fi in the office is frustrating and surprisingly common. Before calling for help, there are several things worth checking yourself. This guide covers the most likely causes and the steps to fix them.
Start with the basics
Before looking at hardware or settings, check a few simple things:
- Restart the router and any switches. Leave them off for 30 seconds before turning back on.
- Check whether the slow speed affects all devices, or just specific ones.
- Run a speed test on a device connected by cable. If the wired speed is also slow, the issue is with your broadband connection rather than your Wi-Fi.
- Check whether the problem is at a particular time of day — congestion is often worse mid-morning and lunchtime.
Check router placement
Wi-Fi signal degrades through walls, especially brick and concrete. A router tucked in a corner, inside a cabinet, or on the floor will always underperform. Move it to a central, elevated position — ideally wall-mounted at head height with clear line of sight to where people work. Keep it away from microwaves, cordless phones, and other wireless devices.
Switch to the 5GHz band
Most modern routers broadcast on both 2.4GHz and 5GHz. The 2.4GHz band has a longer range but is shared by more devices and networks — it congests quickly in offices and shared buildings. The 5GHz band is faster and less congested, but has shorter range. For devices that are close to the router, connecting to 5GHz is usually faster. Check your router admin settings or your device's Wi-Fi list — the 5GHz network often has a "5G" suffix.
Check for channel congestion
In office buildings, multiple businesses often run networks on the same Wi-Fi channel. This causes interference that slows everyone down. You can use a free app such as Wi-Fi Analyser to see which channels nearby networks are using, then log into your router and manually switch to a less crowded channel. On 2.4GHz, channels 1, 6, and 11 don't overlap — pick the least-used one.
Consider adding access points
A single router is rarely enough for an office over 500 sq ft, or any space with multiple rooms or floors. Additional access points extend coverage properly — unlike Wi-Fi extenders, which can actually reduce speeds by halving bandwidth. If your office has dead zones or inconsistent coverage, this is usually the right fix.
Check the hardware age
Routers degrade over time and older hardware doesn't support current Wi-Fi standards. If your router is more than four or five years old, it may be limiting your speeds regardless of your broadband package. Upgrading to a Wi-Fi 6 (802.11ax) router can make a significant difference in an office environment.
When to call for help
If the problem persists after the steps above, or if you are not sure where to start, an on-site visit from an IT engineer is the most reliable route. An engineer can test signal strength across the office, identify interference sources, check switch and cabling quality, and recommend the right hardware setup. For businesses relying on Wi-Fi throughout the working day, getting this right is worth the time.
London-based Wi-Fi support
If the issue keeps coming back or affects multiple users, we can visit your office and diagnose it on-site.
View Wi-Fi and network support →Common questions
Why is my office Wi-Fi slow?
The most common causes are router placement (too far from users or obstructed), channel congestion (neighbouring networks using the same frequency), outdated hardware, or too many devices sharing a single access point. In older buildings, thick walls and interference from other equipment can also play a role.
Can a single router cover an entire office?
It depends on the size of the office. A single router works well in a small, open space. Larger offices, multi-floor workplaces, or buildings with solid walls typically need additional access points to provide consistent coverage throughout.
What is Wi-Fi channel congestion?
Wi-Fi networks operate on shared frequency channels. If several nearby networks use the same channel — which is common in office buildings — they interfere with each other and slow everything down. Switching to a less congested channel or using the 5GHz band can help significantly.
When should I call an IT professional about Wi-Fi?
If you have tried the basic steps and the problem persists, or if the issue is affecting multiple users across the office, an IT professional can carry out an on-site diagnosis, test signal coverage, identify interference sources, and recommend a more permanent fix.
Need help with office Wi-Fi?
We provide on-site Wi-Fi and network support for London businesses. If remote troubleshooting isn't cutting it, we can visit and sort it out properly.