To make use of this scheme, you will need to show your Ukrainian passport and a boarding pass or ticket showing your arrival into the UK. The offer is valid across all train operators in England, Scotland and Wales, and you will have 48 hours from arrival in the UK to complete your journey.
You will be able to use London Underground/DLR services if your journey requires you to travel between London national rail stations.
For the latest scheme information, please visit www.nationalrail.co.uk/ukraine
Further guidance can be found here www.gov.uk/government/publications/welcome-a-guide-for-ukrainians-arriving-in-the-uk
They have 48 hours to make their onward journey. They only need to show a Ukrainian passport and a boarding pass or ticket showing arrival into the country within the last 48 hours.