https://firearms-united.com/2016/12/13/let…er-parliaments/
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Introduction of the Deac-Reg caused problems for legitimate holders of deactivated firearms such as historical re-enactors and those involved in film making etc, as it prohibits them from selling or transferring across borders any items deactivated prior to April 2016 unless the items are re-deactivated to the new standard, which is not technically possible in many cases.
Following pressure from the Parliament there will now be a process to assess national standards in use prior to April 2016. If the standards are accepted by the Working Group and Commission as “equivalent” then items deactivated to that previous regime will be able to be bought, sold and transferred without requiring further modification."