This Technical Specification specifies principles, requirements and guidelines for the quantification and communication of the carbon footprint of a product (CFP), based on International Standards on life cycle assessment (ISO 14040 and ISO 14044) for quantification and on environmental labels and declarations (ISO 14020, ISO 14024 and ISO 14025) for communication. Requirements and guidelines for the quantification and communication of a partial carbon footprint of a product (partial CFP) are also provided. This Technical Specification is applicable to CFP studies and different options for CFP communication based on the results of such studies. Where the results of a CFP study are reported according to this Technical Specification, procedures are provided to support both transparency and credibility and also to allow for informed choices. This Technical Specification also provides for the development of CFP-product category rules (CFP-PCR), or the adoption of product category rules (PCR) that have been developed in accordance with ISO 14025 and that are consistent with this Technical Specification. This Technical Specification addresses only one impact category: climate change. Offsetting is outside of the scope of this Technical Specification.