Engineering work is taking place overnight on some platforms in Cardiff Central station, closing some lines.
The following trains will be amended:
Sunday
The 19:30 Manchester Piccadilly to Swansea will be diverted via Llantwit Major and run later to Swansea.
The 21:16 Carmarthen to Hereford will be diverted via Llantwit Major and run later to Hereford.
The 22:30 Cardiff to Carmarthen will be diverted via Llantwit Major and run later to Carmarthen.
Monday
The 05:43 Swansea to Manchester Piccadilly will start at Cardiff.
Check before you travel:
You can plan your journey using the National Rail Enquiries Journey Planner