Passengers travelling on ferries between the UK and Ireland will need to show their passport from Monday.
Ferry operator Irish Ferries said the new requirement applies to their Dublin to Holyhead and Rosslare to Pembroke routes, in both directions.
Stena Line said all passengers travelling from Dublin, Holyhead, Fishguard or Rosslare ports would also be required to present a valid passport at check-in.
Previously, passengers were able to use other forms of ID, such as driving licences and national identity cards – but the changes are being brought in to comply with UK Border Force rules.
In a statement on its website, Stena Line said the change would meet UK Border Force requirements “in relation to the accuracy and integrity of passenger data before boarding”.
Irish Ferries said the requirement would apply to all passengers, including Irish and UK citizens, adding that from Monday, driving licences, national identity cards and other forms of photographic identification would no longer be accepted on the two routes in question.
Irish Ferries said passengers who were not British or Irish citizens and were visiting for a short stay of up to six months in the UK may need an Electronic Travel Authorisation (ETA), which allows travel to the UK, Jersey, Guernsey or the Isle of Man for up to six months.
Passport cards will also be accepted by both operators.