Commission Implementing Regulation (EU) 2025/1182 of 17 June 2025 establishing detailed rules on the rescaling of harmonised indices to the common index reference period 2025 pursuant to Regulation (EU) 2016/792 of the European Parliament and of the Council

1 The new common index reference period for the harmonised indices referred to in Article 1 of Regulation (EU) 2016/792 and their subindices shall be 2025.

2 Member States shall apply the new common index reference period for the harmonised indices and subindices, including any data revisions, transmitted to the Commission (Eurostat): (a) for monthly indices, starting with the index for January 2026 and onwards; (b) for quarterly indices, starting with the index for the first quarter of 2026 and onwards.

1 Member States shall calculate rescaling factors with a precision of at least six decimal places for each of the harmonised indices and their subindices according to the following formula: (a) for monthly indices: rescaling factor monthly11212m1ChI2015100,m2025100 (b) for quarterly indices: rescaling factor quarterly144q1ChI2015100,q2025100 where: ChI2015100,m2025 is a chained Laspeyres-type index for month m of year 2025, with 2015 = 100 as the index reference period; ChI2015100,q2025 is a chained Laspeyres-type index for quarter q of year 2025, with 2015 = 100 as the index reference period.

2 The full time series of the harmonised indices and their subindices, including any revised data, shall be rescaled to the new common index reference period using the rescaling factors referred to in paragraph 1.

3 Member States shall transmit the calculated rescaling factors to the Commission (Eurostat): (a) no later than 21 January 2026, for the monthly indices; (b) no later than 30 April 2026, for the quarterly indices.

4 The Commission (Eurostat) shall use the rescaling factors referred to in paragraph 3 to rescale the full time series of harmonised indices and their subindices previously transmitted by the Member States.

5 In the event of a revision of the harmonised indices and subindices for any reference period of the year 2025 that takes place after the dates indicated in paragraph 3, the Member States shall transmit to the Commission (Eurostat) the updated rescaling factors together with the revised full time series based on 2025 = 100 without unjustified delay.

This Regulation shall enter into force on the twentieth day following that of its publication in the Official Journal of the European Union.