This document specifies general requirements for sampling, preservation, handling, transport and storage of all water samples for physicochemical, chemical, hydrobiological and microbiological analyses and radiochemical analytes and activities. Guidance on the validation of storage times of water samples is provided in ISO/TS 5667-25. It is not applicable to water samples intended for ecotoxicological assays, biological assays, passive sampling as specified in the scope of ISO 5667-23 and microplastic particles and fibres. This document is particularly appropriate when samples cannot be analysed on site and have to be transported to a laboratory for analysis. This document and the analytical International Standards can be used as presented in Figure 1.