Engineering work is taking place between Nunhead / Beckenham Junction and St Mary Cray / Petts Wood, closing all lines.
On Saturday, buses will replace trains between Bromley South and Orpington.
On Sunday, buses will replace trains between Beckenham Junction and Orpington, and trains between London Victoria and Ramsgate / Dover Priory / Ashford International via Maidstone East will be diverted not to call at Bromley South. Additional trains will run between Grove Park and Bromley North, calling at Sundridge Park.
For Bromley South, you can use your tickets at no extra cost on Thameslink replacement buses between Bromley South and Swanley to connect with diverted trains.
On Sunday only, buses will replace trains between London Bridge and Swanley, calling at all stations except Nunhead and Ravensbourne.
For Nunhead / Ravensbourne, you can use paper rail tickets at no extra cost on London Buses to complete your journey.
A revised train service will run between Swanley and Sevenoaks.
Your tickets will be accepted at no extra cost on Southeastern trains between London Victoria and Otford / Beckenham Junction.
You can plan your journey using the National Rail Journey Planner.
You can plan your journey on London Buses by using the Transport for London Journey Planner.
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.