(6) If the aeroplane operator’s annual CO$_{2}$ emissions from international flights increases above the threshold of 500,000 tonnes in 2019, the Regulator may permit the aeroplane operator to continue to apply the monitoring method chosen in accordance with paragraph (5) for this period. 

## 2021-2035 period 

(7) An aeroplane operator, with annual CO$_{2}$ emissions from international flights between State Pairs defined in the ICAO document entitled “CORSIA States for Chapter 3 State Pairs”( a ) of greater than or equal to 50,000 tonnes, must use a Fuel Use Monitoring Method as described in Schedule 2 for these flights. For other international flights, the aeroplane operator must use either a Fuel Use Monitoring Method, as described in Schedule 2, or the CERT, as described in Schedule 3. 

(8) An aeroplane operator, with annual CO$_{2}$ emissions from international flights between State Pairs defined in the ICAO document entitled “CORSIA States for Chapter 3 State Pairs” of less than 50,000 tonnes, must use either a Fuel Use Monitoring Method or the CERT as described in Schedules 2 and 3, respectively. 

(9) If an aeroplane operator’s annual CO$_{2}$ emissions from international flights between State Pairs defined in the ICAO document entitled “CORSIA States for Chapter 3 State Pairs”, increases above the threshold of 50,000 tonnes in a given year (y), and also in year (y+1)( b ), the aeroplane operator must— 

(a) submit an updated Emissions Monitoring Plan by 30th September of year (y + 2)( c ), and 

(b) change to a Fuel Use Monitoring Method, as set out in Schedule 2, on 1st January of year (y + 3)( d ). 

(10) If an aeroplane operator’s annual CO$_{2}$ emissions from international flights between State Pairs defined in the ICAO document entitled “CORSIA States for Chapter 3 State Pairs” decreases below the threshold of 50,000 tonnes in a given year (y), and also in year (y + 1), the aeroplane operator may change monitoring method on 1st January of year (y + 3). 

(11) Where an aeroplane operator chooses to change its monitoring method under paragraph (10)( e ), it must submit an updated Emissions Monitoring Plan by 30th September of year (y + 2). 

(12) Where the aeroplane operator has, prior to this Order coming into force, accumulated any fuel use during 2021 pursuant to article 3 of Commission Implementing Regulation (EU) 2019/1603 in conjunction with article 24 of the UK ETS Order, that fuel use data must be used for the purpose of this Order 

## Emissions Monitoring Plan 

23. —(1) An aeroplane operator must submit an Emissions Monitoring Plan to the Regulator for approval by the Regulator. The Emissions Monitoring Plan must contain the information set out in Schedule 4. 

(2) Where an aeroplane operator has, prior to this Order coming into force, established an approved Emissions Monitoring Plan pursuant to article 3 of Commission Implementing Regulation (EU) 2019/1603( f ), a Regulator must, before 30th June 2021, approve and issue an Emissions Monitoring Plan to that aeroplane operator in the same terms, subject to any variation required to comply with this Order. 

(3) A new entrant aeroplane operator must submit an Emissions Monitoring Plan to the Regulator for approval and issue within 3 months of falling within the scope of applicability set 

