Mandatory Fields
This is the part of the Union registry managed by Germany.

Swiss Linking
The linking of the EU ETS with the Swiss emissions trading system has been completed. EUA and aEUA and Swiss allowances (CHU and CHUA) can be mutually transferred and used for surrender in both systems. Initiated transactions to or from Switzerland will be executed on the following dates in 2020: 28.09., 05.10., 19.10., 02.11., 16.11., 30.11., 07.12., 16.12., 17.12., 21.12.

Further information can be found in the following documents from the EU Commission:
FAQ – Part 1

FAQ – Part 2

Calendar for transactions