O 4am ddydd Llun 18 Ionawr 2021, bydd yn rhaid i deithwyr mewnol sy'n cyrraedd ar gwch, awyren neu drên o wledydd y tu allan i'r Ardal Deithio Gyffredin (DU, Gweriniaeth Iwerddon, Ynys Manaw ac Ynysoedd y Sianel) gymryd prawf hyd at 72 awr cyn gadael y wlad y maent ynddi, i helpu i ddiogelu rhag y mathau newydd o coronafeirws fel y rhai a welir ym Mrasil, Denmarc a De Affrica.
From 4am Monday 18th January 2021, inbound passengers arriving by boat, plane or train from countries outside the Common Travel Area (UK, Republic of Ireland, the Isle of Man and the Channel Islands) will have to take a test up to 72 hours before departing the country they are in, to help protect against the new strains of coronavirus such as those seen in Brazil, Denmark and South Africa.