HMRC states:

“We have been made aware of a number of hauliers being turned back when attempting to board on GB routes into the Republic of Ireland due to them having not completed the necessary steps required by Irish Revenue.

One issue in particular is that some hauliers have not met the Pre-Boarding Notification requirement. A summary of this requirement is:

Pre-Boarding Notification (PBN) – Irish Revenue requirement:

Top lines

• If you carry goods from GB to [Republic of] Ireland using a RoRo ferry service (accompanied or unaccompanied), a PBN must be submitted to Irish Customs. This notification must be submitted in advance of the goods leaving GB.
• The haulier is responsible for ensuring that the PBN is submitted using information provided by the importer. However, the PBN may be created by anyone in the supply chain that has the required information.
• Only one PBN should be created per vehicle irrespective of the number of consignments in the vehicle.
• Vehicles will not be allowed to board ferries in GB without a valid PBN.

More detail

• PBNs are created on Irish Revenue’s Customs RoRo Service 
• Irish Revenue has also set up a dedicated email support service to deal with all PBN related queries at customsPBN [at] revenue.ie
• Irish Revenue put a temporary arrangement in place that allowed for the creation of a PBN for goods movements that began before the end of the transition period (31 December) and ended after that date. This temporary arrangement is no longer available for all sailings departing GB on or after 18:00 hours on 5 January 2021.
• For your information, Irish Revenue has issued a press release with advice to hauliers and truck drivers moving goods from GB into Irish ports. Full details are available here: https://www.revenue.ie/en/corporate/press-office/press-releases/2021/pr-010521-advice-hauliers-goods-gb-irish-ports.aspx  
• A PBN user guide has been added to their website. This is available on https://www.revenue.ie/en/online-services/support/documents/help-guides/ros/pbn-user-guide.pdf  

We also understand that some hauliers have not met the requirements for submitting a Safety & Security Entry Summary Declaration (ENS).

7 day ‘in flight’ period

Separately, I also wanted to bring to your attention that the 7 day ‘in flight’ period will come to an end at 00:01 on 8th January and hauliers will need a GMR from this point. It is vital that, from that point, a GMR is completed accurately, and therefore able to be validated, to prevent hauliers from being turned away from check in, this is  specifically for the GB>NI. Here are some links to pages that may be helpful to your members:

Haulier Advice Sites https://www.gov.uk/guidance/haulier-advice-site-locations, 

TSS https://www.tradersupportservice.co.uk/tss,  

Webinars https://www.gov.uk/guidance/help-and-support-for-uk-transition.”