When communicating results from laboratory investigations from the laboratory to the requesters and further between different information systems, it is important that the value as well as the unique identity and name of the laboratory investigation are correctly cited. A committee under the International Federation for Clinical Chemistry and Laboratory Medicine (IFCC) and International Union for Pure and Applied Chemistry (IUPAC) has developed a systematic nomenclature for the correct classification of laboratory investigations. Each generic laboratory investigation is provided with a unique NPU code. The system is in use among approximately 30 different clinical laboratories in Sweden, and has capacity to be the common denominator of all laboratory investigations, and to be used as the identifier in various information systems. The NPU system for the Swedish laboratories is currently administered by EQUALIS and partly financed by the participating laboratories. Other ways of funding, of benefit for the whole health care sector, will be investigated.