You should check your customs channel status as below for Stena Line routes:
Republic of Ireland exports – prior to arriving for check-in at Dublin or Rosslare.
Republic of Ireland imports – during crossing, from around 30 minutes prior to arrival at Dublin or Rosslare.
Please note – where a PBN is required, it is your responsibility to check if an inspection (export or import) is required and to act upon that information. Stena Line are not responsible for the information held or the accuracy of the information on these external government websites and shall have no liability if you do not access these links or fail to act upon the information provided. The websites can also be accessed directly at https://www.revenue.ie/en/customs-traders-and-agents/customs-electronic-systems/customs-roro-service/customs-channel-look-up.aspx in the event that this website, or the above links, are unavailable.