The pledge means payment could be up to seven days quicker for SMEs and up to 28 days quicker for other suppliers.
Network Rail has committed to pay its suppliers immediately, or as close to immediately as possible.
Faster payments are being released to support and strengthen the extensive supply chain that keeps the railway moving.
Network Rail and its supply chain have a key role to play during this Coronavirus pandemic, ensuring that the railway can continue to get critical medical supplies to hospitals, food to supermarkets, and key workers such as doctors, nurses and police officers to their jobs.
Clive Berrington, commercial and procurement director for Network Rail said: “Our priority is to support the supply chain as much as possible through these unprecedented times.
“We have therefore moved all our suppliers to immediate payment terms, or as close as you can get following approval of the invoice, and we expect that to flow down to the supply chain.”
“Together, we can help to ensure we have a strong supply chain when we emerge from this pandemic.”