17070
Free line-test code — option 1 reads your own number
1470
Prefix to reveal a permanently withheld caller ID
31 Jan 2027
Openreach PSTN copper switch-off deadline
24/7
17070 is automated and free from every UK line
The quickest way: dial 17070 from your handset
If your line has a dial tone and a handset is plugged in, dial 17070 and press option 1. This free automated line-test service announces your own landline number out loud within seconds and works on every UK phone line, regardless of who supplies your broadband. The same code is what Openreach engineers use to confirm a newly installed line, which is why it is the single most reliable method when you simply need to know which number is attached to the socket in front of you.
The service is free, automated and available 24/7. Option 2 on the same menu runs a basic ring-back line test, which is useful if you also suspect a fault. There is no need to register, set up an account or wait for an agent — the recorded message plays your number twice and then hangs up.
Four other ways to find your landline number
17070 doesn't work for everyone — Virgin Media cable customers, lines that have been ceased, and freshly migrated VoIP setups sometimes give an error. In those cases, four other methods will retrieve the number, usually within a couple of minutes. Most readers find their landline by combining two of them: ringing their mobile, then double-checking against a bill or the provider app.
- Call your mobile phone from the landline ;
- Check a recent broadband or phone bill ;
- Sign in to your provider's online account or mobile app ;
- Look the line up on the free BT PhoneBook.
1. Call your mobile from the home phone
Pick up the landline, dial your mobile number and wait for it to ring. Your landline number appears on the mobile screen as the incoming caller ID. Hang up after two or three rings so the call doesn't connect or drop into voicemail — most UK landline tariffs bill calls to mobiles by the minute with no inclusive allowance.
If your landline is set to withhold its caller ID, the mobile will display "Number withheld" or "Private". To reveal it for a single call, dial 1470 immediately before the mobile number — for example 1470 07xxx xxxxxx. This temporarily overrides the permanent 141 block. To turn withholding off for good, ask your provider to remove the 141 setting on the account.
No handset? A basic corded phone costs around £10 from Argos, Amazon or Currys and plugs straight into the master socket. On a VoIP or Digital Voice service, the handset connects into the green telephone port on the back of your router rather than a wall socket.
2. Check a recent bill or welcome pack
Every UK broadband and phone bill prints the landline number on the first page, usually next to the account number and address. Paper bills, PDF statements and the welcome letter you received when the line was activated all show it. If you cancelled paper billing, the last few months of statements are stored in your provider's online account.
If no recent bill is to hand, check your bank statement: the direct debit reference often contains the line number, and the box your router shipped in usually has the number printed on the dispatch label. Standalone line rental bills still exist for a small number of legacy customers and follow the same layout.
3. Sign in to your provider's app or online account
Every major UK provider displays the landline number on the dashboard once you sign in. It usually sits under "Your services", "Phone" or "Line details", next to the account number and installation address. Two-factor authentication may be required if you log in from a new device, so have access to the registered email or mobile.
- BT: My BT on bt.com or the BT app — landline shown under "Phone" ;
- Sky: My Sky on sky.com — Sky Talk number is on the main account page ;
- Virgin Media: My Virgin Media — phone number under "Your package" ;
- EE / Plusnet / TalkTalk / Vodafone: the home broadband section of each provider's app shows the landline number on the dashboard ;
- Routers: some modern routers (BT Smart Hub 2, Sky Hub 4 / Glass, Virgin Hub 4 / 5) list the assigned Digital Voice number on the admin page accessed via 192.168.1.254 or 192.168.0.1.
4. Look the line up on the BT PhoneBook
If the line has ever been listed in the directory, the number appears on the free BT PhoneBook after a quick search of the surname and postcode. Since 2020, new BT customers are ex-directory by default, so this method works best for lines that have been at the same address for several years — or for tracing the previous occupant's number if you have just moved in.
A quick alternative if the PhoneBook draws a blank is to ask a close family member or neighbour to check their mobile contacts. Anyone who has called you at home in the last few years probably still has the landline saved.
Contact your broadband or phone provider
When nothing else works, the provider holds your landline number on file and will read it back to you over the phone once they confirm your identity. Data-protection rules mean the agent cannot give it out without security questions, so have the following information ready before you call — or use the in-app live chat if your provider offers it.
- Account number (printed on any bill or welcome email) ;
- Full name of the account holder ;
- Installation address including postcode ;
- Password or memorable word, if one was set on the account ;
- Last four digits of the direct-debit bank account.
If you can't pass security, most UK providers will post the line details to the registered address by recorded delivery within 5 working days. In rare cases — for example, a deceased account holder with no nominated successor — they may decline to disclose it and instead release the number, after which it cannot usually be recovered.
Direct contacts for the main UK providers
Not sure who supplies your line? Check the logo on your router, the direct debit on your bank statement, or look up the company that installed the service. Each linked guide below lists phone numbers, opening hours, online chat, email and social-media support.
Provider contact list reviewed in June 2026.
Digital Voice, VoIP and the 2027 PSTN switch-off
By 31 January 2027, Openreach is retiring the traditional copper-based Public Switched Telephone Network (PSTN) and migrating every UK landline to an internet-based service, marketed as Digital Voice (BT), Sky Talk on broadband, Virgin Media Talk or VoIP. Your landline number stays exactly the same during the migration — the only change is that the handset now plugs into the green telephone port on the back of your router instead of a wall socket.
If you have already been migrated and can no longer remember the number, the 17070 line-test still works on the vast majority of Digital Voice and VoIP lines. The number is also displayed inside the provider app — BT Digital Voice, Sky Talk on broadband, My Virgin Media and Vodafone Pro II all show it on the home dashboard. Power-cut resilience packs (a battery backup or a hybrid landline phone, supplied free on request for vulnerable customers and those without a working mobile signal) don't change the number — they simply keep the line working during a power outage.
For background on how the underlying network works and how it relates to your broadband, see our guides on Openreach and VoIP.
My landline has no dial tone — what now?
A silent landline is almost always caused by a handset fault, a disconnected extension or a problem on the Openreach line. Before you report a fault — which can cost up to £155 in engineer charges if the issue turns out to be inside your home — run through this short checklist. It resolves the majority of no-dial-tone problems in under five minutes and tells you which side of the master socket the fault is on.
- If it's a cordless handset, check the battery is charged and the base station is powered ;
- Make sure no other phone in the house is off the hook ;
- Unplug every extension and test at the master socket (the one closest to where the line enters the property) — this isolates internal wiring faults ;
- Swap the handset for one you know works ;
- On a Digital Voice service, restart the router and confirm the green telephone port LED is on.
Still no dial tone? Call your provider from a mobile and ask them to run an Openreach line test. Engineers can usually be booked within 24-48 hours for an urgent fault. While you have the agent on the phone, ask them to confirm the landline number at the same time — it saves a second call later.
Do I still need a landline in 2026?
Not necessarily. Since 2023, most UK broadband providers sell broadband-only packages with no separate phone line, and full-fibre (FTTP) lines from Openreach, Virgin Media, CityFibre, Hyperoptic or Community Fibre don't rely on a copper phone line at all. According to Ofcom, landline call volumes have fallen by roughly 80% over the past decade and most households now make fewer than one call a week from the home phone.
That said, several situations still make knowing — and keeping — your landline number genuinely useful:
- Switching broadband: some providers ask for the current landline number to check line availability and arrange the transfer ;
- Elderly relatives: parents and grandparents often prefer calling a home phone, and Age UK recommends keeping a landline for emergency dialling ;
- Blocking nuisance calls: registering with the free Telephone Preference Service (TPS) requires the landline number and is the most effective way to reduce cold calls ;
- Medical alarms and burglar alarms: some older pendant alarms and intruder systems still dial out via the phone line ;
- Patchy mobile signal: in rural areas and thick-walled buildings, the landline remains the most reliable way to dial 999.
If none of those apply, dropping the line could save £15-£25 a month. See our guide to broadband without a phone line and our roundup of the cheapest broadband deals for flexible alternatives.
How to get rid of your landline (and number)
Cancelling a landline is a single phone call to your provider, but three checks beforehand can stop you being hit with an early-exit fee or losing your broadband by mistake. Most UK providers require 30 days' notice and charge an early-termination fee if you're still inside the minimum term — typically £15-£25 for every month remaining.
- Read your contract for the end date and any early-termination fees ;
- Confirm whether the broadband can continue without the line — on FTTP and Virgin Media cable it can ; on older ADSL and FTTC it usually can't ;
- If you want to keep the number for a future provider, ask for a temporary number porting code before cancellation. Once the line is ceased, the number is released back to the originating exchange and is usually impossible to recover.
Broadband without a landline
Full-fibre (FTTP), Virgin Media cable, Hyperoptic, Community Fibre, 4G/5G home broadband and pure VoIP services all work without a traditional phone line. Switching to one of these typically saves £10-£20 a month on a like-for-like speed compared with a copper FTTC bundle. For full comparisons, see our roundups of the cheapest broadband deals, no-contract broadband and the TV & broadband hub.
Frequently asked questions
Dial 17070 from your landline and press option 1. This free automated line-test service reads your own landline number back to you within seconds and works on every UK phone line, including most Digital Voice and VoIP services.
If the line is silent, 17070 will not work. Instead, log in to your broadband provider's online account or mobile app, check a recent bill, or call customer service from your mobile with your account number, full address and postcode ready.
Your provider has set caller ID to permanently withheld. To reveal the number for a single outgoing call, dial 1470 immediately before the mobile number. To remove the block permanently, ask your provider to disable the 141 setting on the line.
No. BT, Sky, Virgin Media and every other UK provider migrate your existing number to Digital Voice or VoIP so you keep the same landline number. The only change is that the handset plugs into the router rather than the wall socket.
Yes, the BT PhoneBook is free and lists residential and business numbers whose owners opted in to the directory. Since 2020 new BT customers are ex-directory by default, so the service works best for long-established lines.
By 31 January 2027 Openreach will have moved every UK landline to a Digital Voice / VoIP service over your broadband router. Your existing number is ported over automatically. If you cancel rather than migrate, the number is released and cannot usually be recovered.
Next steps
Once you have your landline number back, save it in your mobile contacts and write it on the router box so you never have to search for it again. If the whole exercise has convinced you that you rarely use the home phone, this is a good moment to compare broadband-only and full-fibre packages that drop the line rental altogether — and to plan ahead for the 2027 Digital Voice migration if you haven't been switched over yet.