Rachel

Thank you for your question.

If either of your sons can produce something which confirms their residence in Pembrokeshire; such as a passport or driving licence, they can get a Pembrokeshire Railcard.

In addition, and you dont mention how old your sons are, but if either or both are 25 or under, they might want to consider getting themselves a Young Persons Railcard.
It costs £20 and gives anyone aged 16 to 25, or a mature student in full-time education, a third off rail fares across the whole of the UK. It will pay for itself with say just one journey to London

Mark MYoungman@carmarthenshire.gov.uk