
Article 1 
The aim of this Regulation is to establish common rules for determining certain index reference periods in order to ensure that the resulting Harmonised Indices of Consumer Prices (HICPs) are comparable and relevant.
Article 2 
There shall be three types of common reference or base periods used in the construction of HICPs which may be chosen independently of each other, namely:

((a)) The ‘weighting reference period’ is as defined in Article 2 of Commission Regulation (EC) No 2454/97.
((b)) The ‘price reference period’ is the period from which the current price change is measured and for which prices are used as denominators in the index calculations; it refers to the prices used for the volume valuation in the HICP weights.
((c)) The ‘index reference period’ is the period for which the index is set to 100 index points.
Article 3 

1. The HICP common index reference period shall be set at 2005 = 100.
2. The full time series of the HICP all-item indices and sub-indices shall be rescaled to another common index reference period when deemed appropriate. Upon updates, the full time series of all HICPs and HICP sub-indices shall be rescaled to the common index reference period. The rescaling to the new index reference period shall take effect with the index for the January of the following calendar year.
3. The Commission (Eurostat) may update the index reference period after consulting the Statistical Programme Committee established by Decision 89/382/EEC, Euratom.
4. Any additional COICOP/HICP sub-indices to be integrated within the HICP shall be linked in December at the level of 100 index points and take effect with the index for the following January.
Article 4 
Article 4 of Regulation (EC) No 2214/96 is replaced by the following:
'
Article 4 
The Commission (Eurostat) shall disseminate sub-indices of the HICPs for the categories listed in Annex 1 to this Regulation on the basis of a common index reference period'.
Article 5 
This Regulation shall enter into force on the twentieth day following its publication in the Official Journal of the European Union.
This Regulation shall be binding in its entirety and directly applicable in all Member States.Done at Brussels, 19 October 2005.
For the Commission
Joaquín ALMUNIA
Member of the Commission