Ar 1 Hydref 2011 Cymru oedd y wlad gyntaf ym Mhrydain i gyflwyno isafswm tâl o 5c am bob bag siopa untro. Yn y bum mlynedd ers hynny, mae’r polisi wedi arwain at ostyngiad sylweddol yn y defnydd o’r mathau yma o fagiau, a mwy o gefnogaeth ymysg cwsmeriaid i’r tâl.  Yn dilyn y llwyddiant hwn, mae gwledydd eraill ledled Prydain wedi mabwysiadu polisïau tebyg.
On 1 October 2011 Wales became the first country in the United Kingdom to introduce a minimum charge of 5p on all single use carrier bags. In the intervening five years the policy has resulted in a  significant reduction in the use of these types of bags and an increase in support among consumers for the charge. Following this success, other countries across the UK have adopted similar policies.