Previously, as has been the case across much of the UK Rail industry, hot drinks were only served from disposable cups for safety and stock control reasons.
But following calls from customers and a health and safety review, Arriva Trains Wales is delighted to be able to serve customers their drinks in their own cups or mugs, provided they also include a secure lid.
Head of Customer Experience Barry Lloyd said: "This is an example of how we have listened to our customers and found a practical solution together with our At Seat Catering team to the benefit of customers and the environment.
"We have always been passionate about reducing our carbon footprint, and whilst the cups currently used by our At Seat Catering team do recycle, this will go a step further and give customers more choice."
The change will come into effect on Monday, 15th January and for a limited time customers will be able to purchase a hot drink and an Arriva Trains Wales travel mug with secure lid for only £5.