Engineering work is taking place between London Kings Cross and Potters Bar, and also between Potters Bar and Letchworth Garden City, closing all lines early on Sunday morning.
Until approximately 08:20 on Sunday, buses replace trains between Potters Bar and Letchworth Garden City.
Additionally, until approximately 05:30, buses replace trains between London Kings Cross and Potters Bar.
Check before you travel:
You can plan your journey using the National Rail Enquiries Journey Planner.
Replacement bus travel advice:
For helpful advice if you need to travel on a rail replacement service, including accessibility and bicycle information, please use our Rail Replacement Services page.
You can find the pick-up and drop-off location of rail replacement services by checking station signage or by searching for your station on our Find a Station page.
Please be advised that replacement vehicles may be busier than usual, and you should allow extra time for your journey.