Operation Genesis will see extra officers and rail staff out across the network throughout the month to help anyone who needs it.
With emphasis on Fridays and Saturdays during December, the operation will see an increase in high-visibility patrols on trains and at stations, as well as covert policing to target issues including sexual harassment, anti-social behaviour and alcohol-related disorder.
Passengers will also continue to be reminded of the need to wear a face covering when using public transport, unless they have an exemption.
The operation aims to prevent crime and anti-social behaviour, as well as provide reassurance and personal safety advice to the public.
BTP Superintendent for Wales, Andy Morgan, said: “We want to everyone to enjoy the festive season and we’ll be working closely with our partners to make sure everyone gets home safely.
“Rail is one of the safest ways to travel - but, we see how alcohol can really affect judgement, people often take greater risks, and standards of decency and general behaviour can worsen.
‘‘We urge passengers to take extra care of themselves and others during this period to make sure they have a safe journey and take responsibility for their own behaviour.
“As well as having extra officers on hand across the network, we want to remind passengers of our discreet text service.
‘‘Save the number ‘61016’ in your phone, in case you ever need our assistance on the railway.”
Leyton Powell, Transport for Wales’ safety and sustainability director, said: “The Wales and Borders network is one of the safest in the UK, thanks to the hard work of TfW and BTP staff and the responsible behaviour of the vast majority of our passengers.
“In collaboration with BTP we are taking extra steps to ensure our services remain safe during what is likely to be a busy festive period.
‘‘We want to reassure our customers that extra staff on trains and stations, especially on weekends, are there to help keep everyone using our network safe.”
If you see something that doesn’t seem right, text BTP on 61016 or call 0800 40 50 40. Alternatively, contact Crimestoppers anonymously on 0800 555 111