‘The WiFi is bad’ covers three different faults, and they have three different fixes. The broadband line into the building can be too slow or too busy. The wireless network inside the building can have gaps, interference or too many devices on one box. Or a single laptop can be the problem while everyone else is fine. Office WiFi problems often drag on because businesses fix the wrong issue first. Many reach for a new router, even when the real problem lies elsewhere.
Three checks, in the right order, narrow it down. None of them proves a fault on its own, but together they tell you which conversation to have. This also tells you which purchase to hold off on. Here is the order an engineer would use, what each result suggests, and what to do once you know.
First check: is it the line?
Everything in the office shares one connection to the outside world, so start there. Take a laptop with a gigabit port to the router or the switch it feeds, and plug in with the router’s own cable. Next, switch the laptop’s WiFi off and run a speed test. Ofcom gives broadband speed advice mainly for home users. However, its first tip applies to businesses too: connect a device directly to the router with an Ethernet cable. For diagnosis that matters because a cabled test takes the wireless network out of the picture.
Compare the result with the speed estimate from your provider, as business broadband is often sold as ‘up to’.
If the cabled speed is close to that figure and stays stable, the broadband line is likely working as expected at that time. That points to an issue inside the building instead.
Repeat the test during your busiest period before ruling out the broadband connection completely. If it is well below the estimate, or it swings around from one minute to the next, the problem starts at or before the router. Therefore, no amount of WiFi equipment will help.
Two things make a line look worse than it is.
Timing
An office that is fine at 8am and crawling at 11am can point to a contended broadband product, shared with other customers on the provider’s network. However, it can equally be the office’s own equipment saturating when everyone arrives. A cabled test at 11am separates the two: slow on the cable and the line is the suspect, fine on the cable and the problem is inside.
The plan itself.
A connection sold years ago for email may never have been sized for thirty people on video calls. The difference between a leased line and business broadband is mostly about that: guaranteed speed in both directions, and nobody else on it. For scale, Microsoft’s network guidance for Microsoft Teams recommends 1.5 Mbps each way per device for a good one-to-one video call, and 2.5 Mbps up and 4 Mbps down for a group meeting. Teams can run on far less than that and will sacrifice video before audio, so treat those as comfort figures. Even so, multiply them by the number of people on calls at once. A plan sized years ago for email becomes a suspect worth raising with the provider.
Second check: is it the office WiFi itself?
If the cable test passed, stay on the laptop, switch WiFi back on and run the test twice: once standing next to the router or access point, once in the room where the complaints come from.
Good next to the box, poor in the room suggests coverage.The WiFi signal weakens as it travels. Distance, thick or metal-framed walls and rows of steel filing cabinets can all cause problems.Sometimes, businesses put an access point in a cupboard simply because the cabling ends there.In that case, moving the access point or adding another one can help. A stronger router will not solve the problem because one router cannot cover every area equally well.
Poor everywhere on WiFi, fine on the cable points at the wireless equipment itself, once a second laptop shows the same result, which rules out the device (the third check below). One common cause in a small office is a consumer-grade router doing a job it was never designed for; others are channel congestion from neighbouring networks, or an old access point, or a single box serving a floor it cannot reach.
A consumer router is built for a household. An office of twenty-five people has phones, laptops, printers, a smart TV in the meeting room and a card machine. Every one of them is competing for airtime on the same radios. Symptoms are the mid-morning slowdown that clears at lunch, and devices that show as connected but no internet reaches them. When the equipment is the cause, the fix is a business access point, or several, each wired back to the switch, so that devices spread across them. A survey tells you which of those causes you have before anything is bought.
Office WiFi that keeps dropping in one meeting room during calls can be both at once: the room is at the edge of coverage. A call notices packet loss long before a web page does.
Check which WiFi band the laptop is using
One detail worth checking while you are standing in the problem room: which network name the laptop is on. Many routers broadcast two, one on the 2.4 GHz band that travels further and one on 5 GHz that carries more. A laptop that latched onto the far-reaching band at the front door and never let go will be slow at the back of the building even when a better signal is available.
Third check: is it the laptop?
If the cable test passed and a colleague’s laptop in the same room is fine, the problem is most likely the device, which is the answer to a question people ask constantly: why is my laptop not connecting when the WiFi is working for everyone else?
The common causes are dull and quick to fix:
- a wireless adapter driver that has not been updated since the laptop was bought
- a power-saving setting that turns the adapter off during a long call
- an older machine with a card that only understands the slower band
- a VPN client routing every packet through a server in London before it reaches the printer two metres away
None of these is a network problem, and the person who fixes them is whoever supports the laptops.
What each result points to
| Result | What it suggests | The next step |
| Slow or unstable on a cable at the router, including at the busy hour | The line, or the router it lands on | A conversation with the provider first; a bigger or guaranteed product only once the busy-hour tests confirm it |
| Fine on a cable, poor on wireless in some or all rooms, on two laptops | The wireless network: coverage, congestion or equipment | A wireless survey with a heat map before any equipment is bought |
| Poor on one device, fine on the next one | That device | A support ticket for driver, power and VPN settings |
A new router helps in one case: when the old router was the cause, which the second check and a survey establish. It will not make a slow line faster, and it will not reach a back office through two brick walls.
Before you buy anything
Write down the three results with the times you ran them; they are the first thing any engineer will ask for. If the cable test failed, the call is to the broadband provider, with the numbers. The cable passed and the wireless did not, so the next step is a survey, not a purchase: The Unite Group’s surveys and heat maps show where the signal goes and where it dies. This is what decides whether the answer is placement, cabling to a second access point, or new equipment. If one laptop is the odd one out, it is a support ticket, and the quickest of the three to close through managed IT services.