Train services across southern England have experienced disruptions following a fault with a radio system.
National Rail Enquiries said the issue relates to how train drivers and signallers communicate.
It warned passengers that services may be delayed by up to 90 minutes or cancelled, and “major disruption is expected until the end of the day”.
The affected operators are CrossCountry, Gatwick Express, Great Western Railway, London Overground, Southern, South Western Railway (SWR) and Thameslink.
The incident was reported shortly before 9am on Thursday.
SWR warned that services across its entire network “may be cancelled, delayed by up to 90 minutes or revised”.
It went on: “Our operations and engineering teams are working with signallers to find and fix the fault.
“We do not have an ETA (estimated time of arrival) yet for when signalling will be back to normal.”
The operator advised passengers to consider using buses “while the fault is being investigated”.
Key Points
- Train passengers across southern England warned of ‘major disruption’
- Which train companies are affected?
- South Western Railway warns services affected across 'entire network'
- What is the fault causing the disruption across train services?
- What are your rights if your train is cancelled or delayed?
- Waterloo arrivals and departures in disarray
What is the fault causing the disruption across train services?
14:30 , Maryam Zakir-HussainTrain services across southern England are being disrupted by a fault with a radio system.
National Rail Enquiries said the issue relates to how train drivers and signallers communicate.
What are your rights if your train is cancelled or delayed?
14:05 , Maryam Zakir-HussainTrain journeys are often disrupted, as we can see from today’s travel chaos with South Western Railway. Passengers who are caught up with long delays and cancellations are entitled to a partial refund – or the full cost of the ticket for a really long delay.
But the rules are complex and change from one train operator to another. And Eurostar, which runs trains from London to Paris, Brussels and Amsterdam, has a quite different policy on delays.
These are the key questions and answers:
What are your rights if a train is cancelled or delayed?
Gatwick Express services likely to run to/from Brighton
13:40 , Maryam Zakir-HussainGatwick Express services are now likely to run to/from Brighton, rather than terminating at Hayward Heath, the operator said.
ℹ️ Gatwick Express services are now likely to run to/from Brighton, rather than terminating at Hayward Heath.
— Gatwick Express (@GatwickExpress) May 7, 2026
📲 You should continue to check the Gatwick Express app, or our website, for the latest information regarding your journey: https://t.co/ZTUEaFZc41
Thameslink give update
12:53 , Maryam Zakir-HussainThameslink has said the disruption has now ended.
The operator said in a post online: “If you've been delayed at your destination by 15 minutes or more, you should apply for Delay Repay compensation.”
✅ Disruption due to this issue has now ended.
— Thameslink (@TLRailUK) May 7, 2026
🌐 If you've been delayed at your destination by 15 minutes or more, you should apply for Delay Repay compensation: https://t.co/WxPaQiBDgv
Great Western Railway: 'Services no longer affected'
12:27 , Maryam Zakir-HussainGreat Western Railway has said the communication systems has now been resolved and services are “no longer affected”.
✅ Travel Update - 07/05 ✅
— GWR (@GWRHelp) May 7, 2026
Disruption caused by issues with communication systems has now ended.
Services are no longer affected by this problem
Check your journey at https://t.co/FUh5xp6dAO and follow us for updates. pic.twitter.com/lagj7lElAn
National Rail Enquiries says delays up to 90 minutes expected
11:54 , Maryam Zakir-HussainNational Rail Enquiries said some services may still be delayed “by up to 90 minutes or cancelled whilst service recover”.
“Major disruption is expected until the end of the day,” an update added.
A Network Rail spokesperson said: “Due to issues with radio communications, train services in the South West and south have been subject to some delays this morning.
“Staff have worked to resolve the fault, and train services are now returning to normal.
“We apologise to passengers for the disruption caused to their journeys.”
Waterloo arrivals and departures in disarray
11:43 , Maryam Zakir-HussainOur travel correspondent Simon Calder writes:
The busiest station in the UK for “normal” trains (excluding the Elizabeth line) is London Waterloo.
It is the hub for state-run South Western Railways.
Data from RealTimeTrains.co.uk shows delays of over an hour beginning at around 9am, with trains from Reading, Portsmouth and Honiton in Devon arriving over an hour behind schedule.
The train due in from Windsor at 9.23am finally arrived at platform 14 at 11.09am, nearly two hours late.
Many trains due to operate were cancelled due to rolling stock, drivers and guards out of position.
Even though the systemwide fault is now fixed, delays and cancellations are likely to continue into the afternoon and possibly affect the evening rush-hour.
The compensation bill for delay repay is likely to run into hundreds of thousands of pounds on South Western Railway alone.
Have you been affected? Get in touch
11:27 , Maryam Zakir-HussainIf you have been affected by this morning’s rail disruption, we want to hear from you.
Get in touch by emailing maryam.zakir-hussain@independent.co.uk
National Rail: Disruption towards Haywards Heath expected until 1pm
11:24 , Maryam Zakir-HussainNational Rail has said disruption towards Haywards Heath is expected until 1pm.
The operator said passengers can travel on the following lines at no additional cost:
- Thameslink services between London and Brighton
- Southern services between London and Haywards Heath
ℹ️ #HaywardsHeath - Disruption through Haywards Heath expected until 13:00
— National Rail (@nationalrailenq) May 7, 2026
'Very rare' radio fault responsible for today's delays also happened in 2024
11:19 , Maryam Zakir-HussainThe radio fault that took train lines down this morning also occurred in December 2024.
The nationwide fault was linked to faulty GSM-R radio systems, which allow communication between train drivers and signal operators.
Widespread delays also took place in 2024 as a consequence of the radio fault.
Speaking to Sky News during the 2024 disruption, railway journalist Nigel Harris said the fault was "very, very rare" and something he had not experienced in 40 years of working in the industry.
Mapped: Disruption across train lines
11:14 , Maryam Zakir-HussainWhat are your rights if your train is cancelled or delayed?
11:06 , Maryam Zakir-HussainTrain journeys are often disrupted, as we can see from today’s travel chaos with South Western Railway. Passengers who are caught up with long delays and cancellations are entitled to a partial refund – or the full cost of the ticket for a really long delay.
But the rules are complex and change from one train operator to another. And Eurostar, which runs trains from London to Paris, Brussels and Amsterdam, has a quite different policy on delays.
Travel correspondent Simon Calder has the key questions and answers:
Gatwick Express: Radio fault incident 'resolved' but delays and cancellations remain
10:59 , Maryam Zakir-HussainGatwick Express has said the fault with the radio system “has now been resolved” but services can still expect delays or cancellations.
A statement on their website said: "The fault with the radio system between the driver and the signaller that is affecting services on the South England network has now been resolved. Some services may still be delayed by up to 90 minutes or cancelled whilst service recovers.
“Major disruption is expected until the end of the day.”
What is the fault causing the disruption across train services?
10:39 , Maryam Zakir-HussainTrain services across southern England are being disrupted by a fault with a radio system.
National Rail Enquiries said the issue relates to how train drivers and signallers communicate.
South Western Railway warns services affected across 'entire network'
10:33 , Maryam Zakir-HussainSouth Western Railway warned that services across its entire network “may be cancelled, delayed by up to 90 minutes or revised”.
It said: “Our operations and engineering teams are working with signallers to find and fix the fault.
“We do not have an ETA (estimated time of arrival) yet for when signalling will be back to normal.”
The operator advised passengers to consider using buses “while the fault is being investigated”.
Which train companies are affected?
10:29 , Maryam Zakir-HussainThe affected operators are CrossCountry, Gatwick Express, Great Western Railway, London Overground, Southern, South Western Railway (SWR) and Thameslink.
The incident was reported shortly before 9am on Thursday.
BREAKING: Train passengers across southern England warned of ‘major disruption’
10:24 , Joe MiddletonTrain services across southern England are being disrupted by a fault with a radio system.
National Rail Enquiries said the issue relates to how train drivers and signallers communicate.
It warned passengers that services may be delayed by up to 45 minutes or cancelled, and “major disruption is expected until the end of the day”.
