To make sure that the security and safety of the EU is maintained across the EU external border it is necessary to make an adjustment in the coordinated and gradual approach for deployment of the ICS2 Release 2, described in the "Transition from ICS2 release 1 to release 2 strategy". The change affects the air carriers operating direct flights from third countries into Member States which have been granted the derogation to connect to ICS2 Release 2 central system until 30 June 2023 (Austria, Belgium, Denmark, Estonia, France, Greece, Croatia, Luxemburg, Netherlands, Poland, Romania, Sweden).:
ICS2 Release 2 will be launched on 1 March 2023 and by this date EU Member States (including in this respect Norway and Switzerland) are expected to be ready with the implementation of their relevant ICS2 National Entry Systems (NES). However, some EU Member States will not be able to connect to ICS2 Release 2 on 1 March 2023 and requested legal derogation from this requirement. The EU Commission granted derogation to twelve EU Member States until 30 June 2023.
EU Member States may allow the affected operators to gradually connect to ICS2 Release 2 system until the end of a deployment window, as defined in the Annex of the UCC Work Programme.  
This means that, if requested by the economic operator and allowed by the competent EU Member State (where the EORI number of the economic operator is registered), the economic operator can connect to ICS2 and become operationally ready at a later date after 1 March 2023.. 
To ensure EU level coordination for a smooth transition from ICS2 Release 1 to Release 2, and to facilitate trade operations, the deployment window per different type of EOs is aligned across all Member States through the relevant transition strategy. It is important to note, that at the moment when the economic operator is ready with its ICS2 Release 2 deployment, at the date agreed with the customs authority of the competent EU Member State, the start of ICS2 Release 2 operation of that economic operator also applies in all other EU Member States (and Norway and Switzerland).
However, the delays in the implementation of the EU Member States can lead to the situation when an economic operator (air carrier) would connect to the ICS2 Release 2 sooner than the customs administration of the EU Member State to which the aircraft arrives from a third country. This situation presents operational challenge to that customs administration in terms of performing the necessary security and safety risk analysis and related controls due to absence of the necessary ICS2 data.
To make sure that the security and safety of the EU is maintained across the EU external border it is necessary to have an additional element of the coordinated and gradual approach for deployment of the ICS2 Release 2 described in the relevant transition strategy. It is strongly recommended that EU and non-EU established air carriers and the Member States customs authorities implement transition to ICS2 Release 2 applying the following coordinated approach, depending on the specific scenario:

• Air carriers operating their direct flights from non-EU countries only in the Member State where their EORI number is registered, if ready, they can connect to ICS2 Release 2 and start ENS filing on 1 March 2023. Otherwise, they must request a deployment window in that Member State to connect to ICS2 Release 2 anytime between 1 March 2023 and 1 July 2023
• Air carriers operating their direct flights from non-EU countries to one or several Member States that are connected to ICS2 Release 2, if ready, they can connect to ICS2 Release 2 and start ENS filing on 1 March 2023. Otherwise, they must request a deployment window in that Member State to connect to ICS2 Release 2 anytime between 1 March 2023 and 1 July 2023.
• Air carriers operating direct flights from non-EU countries to several Member States of which one, more or all Member States are subject to derogation, should request for a deployment window from the Member State of EORI registration, until the date when all affected Member States are connected to ICS2 Release 2, but at the latest until 1 July 2023.

The updated information about the plans of start of operation of the Member States can be consulted  here.
The air carriers that are granted with a deployment window, continue applying the current procedures of submitting Entry Summary Declaration (ENS) to ICS1 during the granted deployment window period.
Each air carrier should assess their own situation of how they operate direct flights from third countries into the EU airports of entry and proceed depending on the scenario valid for it accordingly. Even if the air carrier is in a position to connect to ICS2 Release 2 between 1 March 2023 and 30 June 2023, it should make this careful assessment and it is recommended to adjust its plan of deployment based on the above scenarios.
This approach enables the customs authorities to target and control the shipments at the border at the most efficient method available, using smooth and efficient procedures that will not hamper the fluidity of trade in airports.