During a charter party the charterer should not be responsible for CO2eq emissions and subsequent EUA that occur during an offhire.
In the Chartering module the user can add an offhire entry for the a specific charter party with offhire - onhire dates and the consumption of fuel types during the charter party.
After adding the entry (as confirmed) the ETS module will apply it to the period of the offhire entry, matching it with a particular voyage.
Matching an offhire entry to a particular voyage is important since the EUA commitment is directly tied with arrival and destination ports.
The offhire EUA that will be subtracted from the charterer's commitment will therefore be a ratio of the voyage's EUA commitment based on the fuel types, the amount consumed, emissions and exemptions.
After applying the offhire and subtracting it from the charterer's commitment, the offhire will subsequently be added to the owner's commitment.
Offhire EUA commitment is therefore zero-sum, but distributed between owner and charterer, since the goal is to account for all voyage EUA that is to be surrendered to the EU ETS.