What is a mobile hotspot? A plain-English UK guide

A mobile hotspot lets you share your phone's mobile data connection with other devices — a laptop, a tablet, a games console, or even someone else's phone — so they can get online without their own Wi-Fi or SIM. In effect, your phone becomes a small, portable Wi-Fi router, broadcasting an internet connection that runs on your mobile data allowance. It is one of the most useful features on any modern smartphone, and yet many people have never switched it on or are unsure what it costs or whether it is safe. This guide explains exactly what a mobile hotspot is, how it works, how to set one up on iPhone and Android, what it costs on UK networks, how much data it uses, and how to keep it secure. By the end you will be able to get a laptop online from a train, a café or a power cut with confidence.

#What a mobile hotspot actually does

At its simplest, a mobile hotspot takes the internet connection your phone already has — its mobile data, the 4G or 5G signal it uses to load web pages and apps — and re-broadcasts it as a Wi-Fi network that other devices can join. Those devices then get online through your phone, exactly as they would through a home or café Wi-Fi router, except the underlying connection is your phone's mobile data rather than a fixed broadband line. This is why a hotspot is sometimes called tethering: you are tethering another device to your phone's connection. Apple calls the feature Personal Hotspot; Android phones usually call it Hotspot & tethering or Mobile hotspot; the idea is identical across both.

Crucially, the other devices do not need their own SIM, data plan or Wi-Fi access of their own — they only need to be able to join a Wi-Fi network, which virtually every laptop, tablet and console can. That makes a hotspot enormously flexible: a Wi-Fi-only iPad can get online anywhere your phone has signal, a work laptop can connect on a train, and a friend whose phone has run out of data can borrow yours. The trade-off is that everything those devices do online consumes your phone's mobile data allowance, and runs on your phone's battery, so a hotspot is best thought of as a convenient on-demand connection rather than a permanent replacement for home broadband.

#Three ways to share: Wi-Fi, Bluetooth and USB

Although 'hotspot' usually means Wi-Fi sharing, phones actually offer three ways to tether, each with its own balance of convenience, speed and battery use. Wi-Fi hotspot is the most common: your phone broadcasts a Wi-Fi network that multiple devices can join at once. It is fast and flexible, but uses the most battery. Bluetooth tethering pairs a single device to your phone over Bluetooth; it is slower and suited to one device, but uses less battery, which can be handy in a pinch. USB tethering connects a device — usually a laptop — to your phone with a cable; it is the fastest and most reliable option, uses no extra battery (in fact it charges the phone), and is the most secure because nothing is broadcast wirelessly, but it only works for the one device that is plugged in.

For most people, Wi-Fi hotspot is the default choice because it is the easiest and supports several devices at once. But it is worth knowing the alternatives: if your battery is low, Bluetooth tethering stretches it further; if you need the most stable connection for an important video call or a large download, a USB cable to your laptop is hard to beat. All three draw on the same mobile data allowance, so the choice is about convenience, speed and battery rather than cost.

#How to set up a hotspot on iPhone

1. 1

   Open Personal Hotspot

   Go to Settings → Personal Hotspot (it's also under Settings → Mobile Data on some versions). If you don't see it, your plan may not include tethering — contact your network.

2. 2

   Turn on 'Allow Others to Join'

   Toggle it on. Your iPhone will start broadcasting a Wi-Fi network named after your phone.

3. 3

   Set a strong Wi-Fi password

   Tap 'Wi-Fi Password' and choose something long and not easy to guess. This stops strangers using your data.

4. 4

   Connect your other device

   On the laptop or tablet, choose your iPhone's name from its Wi-Fi list and enter the password. Apple devices on the same Apple ID can often connect with no password.

5. 5

   Turn it off when done

   Switch 'Allow Others to Join' back off to save battery and data once you've finished.

On iPhone, the hotspot stays available for a short time after you stop using it and then sleeps to save power, which is why the network sometimes 'disappears' from another device's list — simply re-open the Personal Hotspot screen on the iPhone to wake it. If you have other Apple devices signed in to the same Apple ID, Instant Hotspot lets them connect without a password at all, which is convenient but means you should keep your Apple ID secure. For anything sensitive, a strong manual password is still the safest choice.

#How to set up a hotspot on Android

1. 1

   Open the hotspot settings

   Go to Settings → Network & internet → Hotspot & tethering → Wi-Fi hotspot (wording varies by phone and Android version).

2. 2

   Configure the network name and password

   Set a recognisable network name and a strong password. You can usually also choose the security type (WPA2/WPA3 — pick the strongest offered).

3. 3

   Turn the hotspot on

   Toggle 'Wi-Fi hotspot' on. Your phone now broadcasts the network for other devices to join.

4. 4

   Connect and check

   On your other device, select the hotspot from its Wi-Fi list and enter the password. A status bar or notification on the phone shows connected devices and data used.

5. 5

   Switch off when finished

   Turn the hotspot off to stop using battery and data. Many phones auto-disable it after a period with no devices connected.

Android also exposes Bluetooth and USB tethering on the same 'Hotspot & tethering' screen, so you can pick whichever method suits the moment. Some Android phones add useful extras here too, such as a data limit that turns the hotspot off automatically once a set amount has been used, an auto-timeout when no devices are connected, and the ability to see and block individual connected devices. It is worth exploring these settings once, because they make a hotspot both safer and less likely to burn through your allowance unexpectedly.

#Does a hotspot cost extra? UK networks explained

On most modern UK plans, using a hotspot does not cost anything extra in itself — the data your tethered devices use simply comes out of your existing monthly data allowance, exactly as if you had used it on the phone. So if you have, say, 50GB a month, a hotspot draws on that same 50GB. However, there are important exceptions and caveats worth checking on your specific plan. Some older or cheaper plans, and some 'unlimited' plans, restrict or cap tethering even when phone data is generous — for example by limiting hotspot use to a set number of gigabytes, or by excluding it altogether. A handful of plans treat tethering as a chargeable add-on. The only way to be certain is to check your plan's terms or ask your network directly.

It is also worth keeping an eye on your allowance when you tether, because laptops and tablets tend to use far more data than a phone does — they download bigger files, run desktop websites, sync cloud storage and install updates. That means a hotspot can eat through your allowance much faster than normal phone use, and going over can lead to extra charges or a slowed connection depending on your plan. Checking how much you have left before and after a heavy hotspot session is a sensible habit — our guide to checking your data balance shows how to do it on every UK network in seconds. If you find you tether a lot, it may be worth choosing a plan with a bigger or genuinely unlimited allowance; our best UK mobile network guide compares the options.

#How much data does a hotspot use?

Because a hotspot uses your normal data allowance, the question that really matters is how much data your tethered activity consumes — and the answer depends entirely on what you do. Light tasks are very economical: sending and receiving email, messaging, browsing text-based websites and reading documents use only a few megabytes at a time, so you could work this way for hours on a modest allowance. The data-hungry activities are the ones to watch. Streaming video is by far the biggest consumer — standard-definition video uses roughly a gigabyte an hour and high-definition several times that, so an afternoon of video on a tethered laptop can swallow a large chunk of a monthly allowance. Video calls, large file downloads, cloud backups, software and operating-system updates, and online gaming downloads can all use gigabytes quickly.

The practical lesson is to be deliberate about heavy activities while tethered. If you only need to work, browse and email, a hotspot is light and you will barely notice the data. But before letting a laptop stream video, download a big update, or back up to the cloud over a hotspot, it is worth pausing — those are the moments that empty an allowance. Most laptops let you set a connection as 'metered', which tells the operating system to hold back automatic updates and large background downloads while on that network; turning that on for your hotspot connection is one of the single best ways to avoid nasty surprises. And again, a quick data balance check before and after tells you exactly where you stand.

#Keeping your hotspot secure

A mobile hotspot is a Wi-Fi network, and like any Wi-Fi network it needs to be secured, because an open or weakly-protected hotspot can be used by strangers nearby — using up your data, and potentially exposing your connected devices. The single most important step is a strong, unique password: avoid anything short or obvious, and change the default if your phone set one automatically. Use the strongest security type your phone offers (WPA3 if available, otherwise WPA2). Beyond that, a few habits help: only switch the hotspot on when you actually need it (an off hotspot cannot be attacked), keep an eye on the list of connected devices that both iPhone and Android can show you, and turn it off again as soon as you are done. If you ever see a device you do not recognise connected, change the password immediately — that resets access and kicks off anyone who had the old one.

It is also worth remembering that when you tether, your connected devices are sharing your phone's mobile connection, which is generally encrypted between the device and the network — but the security of what you do online still depends on the websites and apps you use. The usual safe-browsing rules apply: look for secure (https) connections, be cautious with sensitive logins on shared devices, and keep your devices updated. A hotspot is, if anything, often safer than a random public café Wi-Fi network of unknown origin, because you control it and protect it with your own password — provided you actually set that password and keep it strong. The same general caution that protects you from scam calls applies online too: if an unexpected message or pop-up pressures you to act, slow down and verify it, exactly as our who called me guide advises for unknown callers.

#When a hotspot is genuinely useful

It is worth picturing the everyday situations where a hotspot earns its keep, because once you have used it a few times it becomes second nature. The classic case is working away from Wi-Fi: on a train, in a car (as a passenger), at a client's office, or anywhere the available Wi-Fi is slow, unreliable or untrusted — you tether your laptop to your phone and carry on. Another big one is the broadband outage: when your home internet goes down, a phone hotspot keeps the essentials running, from work calls to streaming, until the line is restored, which is why many people treat their phone as a backup connection. Travel is a third: a Wi-Fi-only tablet or laptop can get online wherever your phone has signal, saving you from hunting for hotel or airport Wi-Fi.

Hotspots are also handy for other people and devices: lending a connection to a friend or family member whose phone has run out of data, getting a games console or smart device online temporarily, or setting up a new device that needs internet before its own connection is configured. The common thread is that a hotspot turns 'my phone has signal' into 'all my devices have internet', wherever you are. The main things to keep in mind are the ones this guide keeps returning to — it uses your data allowance and your battery — so it is a brilliant on-demand tool rather than an all-day, every-day replacement for fixed broadband. Used that way, it is one of the most quietly valuable features your phone has.

#Troubleshooting a hotspot that won't work

If your hotspot will not turn on or other devices cannot connect, a handful of checks resolve the great majority of problems. First, confirm your plan actually allows tethering — if the Personal Hotspot or Wi-Fi hotspot option is missing or greyed out, the most common cause is a plan that excludes it, so contact your network. Second, make sure mobile data is switched on and you have signal; a hotspot has nothing to share if the phone itself is not online. Third, check the password is being entered correctly on the other device, and that you are selecting the right network name. Fourth, if a device used to connect but now will not, 'forget' the hotspot network on that device and rejoin it fresh, which clears a stale saved password.

If it still will not work, the usual restart logic applies: toggle the hotspot off and on, toggle the phone's mobile data off and on, or restart both devices. On some phones a hotspot will refuse to start while the phone itself is connected to a Wi-Fi network, so turning the phone's own Wi-Fi off can help. Occasionally the issue is incorrect mobile-data settings on the phone — the so-called APN configuration that tells the phone how to connect to mobile data and tethering — particularly after switching networks or putting a SIM in a different handset; our APN settings guide explains how to check and fix those. The same settings menu where you manage tethering also controls other line features, such as call handling — if you want to tidy those up while you are there, our how to turn off voicemail guide is a handy companion. And if you have simply run out of allowance, the hotspot may connect but nothing will load, which a quick data balance check will confirm.

#Hotspot, tethering and your phone number

One small point that sometimes confuses people: using a hotspot has nothing to do with your phone number or who can call you, and it does not expose your number to the devices that connect. A tethered laptop sees a Wi-Fi network, not your phone number, and connecting to your hotspot does not let another person see, use or 'borrow' your number for calls or texts. Tethering is purely about sharing the data connection. So if you lend your hotspot to a friend, they get internet access on their device but cannot make calls or send texts as you — those still run through your SIM and your phone in the normal way. If you are curious about how numbering and networks relate more generally, our UK mobile networks by prefix guide is a useful primer, though it is a separate topic from tethering itself.

It is also worth distinguishing a phone hotspot from a dedicated mobile broadband device — sometimes called a MiFi or a 4G/5G router — which is a small gadget with its own SIM and data plan whose only job is to broadcast a hotspot. These are popular for people who tether heavily, want to keep their phone's battery free, or need a reliable backup connection at home or in a caravan or holiday let. The principle is identical to a phone hotspot — a SIM's mobile data shared over Wi-Fi — but the device is purpose-built, often has a bigger battery or mains power, and runs on its own separate data allowance. For occasional use, your phone's built-in hotspot is all most people ever need; for constant or heavy use, a dedicated device on its own plan can work out better and saves wear on your phone.

#Bottom line

A mobile hotspot turns your phone into a portable Wi-Fi router, sharing its mobile data with laptops, tablets, consoles and other phones — invaluable when there is no Wi-Fi, during a broadband outage, or when travelling. Setting one up takes seconds on both iPhone (Personal Hotspot) and Android (Hotspot & tethering); the keys to using it well are a strong password, an eye on your data allowance (tethered laptops use it fast), and switching it off when you are done to save battery. On most UK plans hotspot data simply comes out of your normal allowance, but a few plans restrict it, so check yours. For more, see how to check your data balance, fix your APN settings, and compare plans in our best UK mobile network guide.