Thank you for your post.
Safety and Security requirements will still apply for goods being moved using transit, although Entry Summary declarations (ENS) will only be required for movements from the EU to GB from 1 July 2021 as part of the staging-in of controls. As you probably know, if you are completing an Export in GB the EXS can be completed at the same time, but in cases like the example you have given in your query, an export in GB is not required where GB is only acting as a land-bridge.
To ease this type of situation from day 1, there will be a waiver for an EXS to be completed for exiting GB using RoRo for three Months from the 1st January to 31st March 2021. This only applies to RoRo movements where there would normally be a requirement for an EXS and I assume from the anticipated routing in your email, RoRo will be correct in this case.
EXS requirements will apply to other types of movements from Great Britain to the EU from 1 January 2021, and will continue to apply to movements from GB to the Rest of the World.
So, from April 2021 in the land-bridge situation you described, an EXS will be required at the point of exiting GB. From July 2021, there will S&S requirements on both entry into GB and exit from GB.
For joint exit summary declarations and customs export declarations, or for standalone exit summary declarations, the submission is made on CHIEF/Customs Declaration Service and data is shared with the UKS&S system, ‘S&S GB’. SECTION 3.1.5 of the Border Operating Model
provides further detail on S&S requirements.
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