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WI-FI OVER THE FENCE

The signal reaches.
The permission doesn't.

Home Wi-Fi often reaches the house next door, and the street outside.

A plain white home broadband router with small green lights on a windowsill, terraced houses across the street at dusk — AI-generated image, not a photograph of a real person or place.

Being able to see a network is not the same as being allowed to use it. Two UK laws deal with getting a communications service dishonestly and with knowingly unauthorised access to computers.

WPA2/3never set to Open

Check your setting

Keep in mind

Permission matters
Dishonesty is key
Lock your own
Neighbours and Wi-Fi, explained

THE SHORT ANSWER

Two laws
can apply.

One is about obtaining a service without paying,
the other about access you know you are not allowed.

COMMUNICATIONS ACT 2003

Dishonestly obtaining a service

Section 125 makes it an offence to dishonestly obtain an electronic communications service with intent to avoid paying a charge for it.

See the penalties

COMPUTER MISUSE ACT 1990

Knowing it is unauthorised

Section 1 covers access to programs or data that is unauthorised. The CPS notes the person must know it is unauthorised: mere recklessness is not enough.

Common questions

YOUR OWN NETWORK

Lock it, don't leave it open

The NI Cyber Security Centre says use WPA2 or WPA3, change the default Wi-Fi password and never set your network to 'Open'.

Check your setting

CHECK YOUR SETTING

How open is
your network?

Pick the security setting your router shows for Wi-Fi. The bar shows how exposed that setting leaves you to people nearby, from official UK guidance.

Wi-Fi security check

Choose a settingOpen (no password)WEPWPAWPA2WPA3

Open (no password)Never use

The NI Cyber Security Centre says never set your Wi-Fi to 'Open'. Get Safe Online warns anyone in range can then use an unsecured router.

WEPOutdated

WEP is one of the older, less secure methods that the NI Cyber Security Centre says should not be used.

WPAOutdated

Plain WPA is also listed as older and less secure, and not to be used for a home network.

WPA2Recommended

WPA2 is one of the two methods the NI Cyber Security Centre recommends. Get Safe Online calls it the highest of WEP, WPA and WPA2.

WPA3Newest

WPA3 is the newest method and is recommended alongside WPA2. Some older devices may not support the higher levels.

Sources: NI Cyber Security Centre, Securing your home network and Wi-Fi; Get Safe Online, Wireless networks and hotspots.

Summarised from the NI Cyber Security Centre's home network guidance and Get Safe Online. Check your own router's settings page or your provider's help pages.

TWO NUMBERS WORTH KNOWING

The maximum
penalties.

The highest sentences each law allows on indictment,
as set out in the legislation and CPS guidance.

5 years

Maximum prison term on indictment

For dishonestly obtaining an electronic communications service; on summary conviction, up to six months, a fine or both.

SECTION 125 · COMMUNICATIONS ACT

2 years

Maximum prison term on indictment

For unauthorised access to computer material, as the CPS legal guidance confirms; or a fine, or both.

SECTION 1 · COMPUTER MISUSE ACT

Maximum penalties from legislation.gov.uk and the CPS. Whether any law applies to a particular situation depends on the facts; this page is general information.

WHAT THE GUIDANCE SAYS

Five checks
at the router.

The NI Cyber Security Centre lists simple steps to stop people nearby using your connection.

Hands plugging a network cable into the back of a plain white router on a wooden shelf — AI-generated image, not a photograph of a real person or place.

Step 1

Change the admin login

Replace the router's default username and password. Attackers know the defaults for most standard devices.

Step 2

Change the Wi-Fi password

Swap the default Wi-Fi password for a strong one that you and your household can remember.

Step 3

Use WPA2 or WPA3

Log into the router to check the encryption method. WEP and WPA are older and less secure.

Step 4

Know what is connected

Many routers list connected devices. Investigate and remove any you don't recognise, and use a guest network for visitors.

WHY AN OPEN NETWORK MATTERS

It is your
connection.

The lit back windows of two neighbouring houses either side of a garden fence in the evening — AI-generated image, not a photograph of a real person or place.

Get Safe Online warns that people within range of an unsecured router can take up your bandwidth, use the download allowance you pay for, and download material that would be traced to your address.

The NI Cyber Security Centre adds that criminals could use a weakly secured connection to carry out illegal activity as if they were you. It also suggests renaming your network so it does not reveal your provider.

Questions

Questions on the way

Is it illegal to use a neighbour's Wi-Fi?

Two laws can apply: section 125 of the Communications Act 2003 (dishonestly obtaining a service to avoid paying) and section 1 of the Computer Misuse Act 1990 (knowingly unauthorised access).

What if my neighbour gave me the password?

Both offences hinge on the use being dishonest or unauthorised. If you are unsure what you have been allowed to do, ask the account holder; this page is not legal advice.

Does section 125 need dishonesty?

Yes. The person must dishonestly obtain the service and do so with intent to avoid payment of a charge for providing it.

Can my Wi-Fi really reach next door?

Yes. The NI Cyber Security Centre says Wi-Fi signals are better than ever, so your connection can be reached outside your home.

How do I see who is on my Wi-Fi?

Many routers show connected devices in real time. The NI Cyber Security Centre suggests investigating and removing any you don't recognise.

Destination

Where the facts come from

Updated 16 October 2026

The signal reaches.The permission doesn't.

Two lawscan apply.