Systematic studies on 14C dating of tufa profiles in southern Poland have resulted in developing a simple phenomenological model which enables the estimation of the reservoir correction factor of 14C dates of individual carbonate samples. Model assumptions were tested and relationships between the value of reservoir correction factor TR and 13C content of tufa carbonate verified. Two new study sites at Rudawa and Szklarka, are close to previously studied sites. Four tufa samples with associated organic fraction from c2000 m asl in South America (Peruvian Andes) were measured to test the possible application of the developed model to tufas in different geochemical and climatic environments. Finally, a series of calcareous tufa samples from the Villers-devant-Orval profile (Belgium) were dated, although no direct comparison with organic matter dates is available for this profile. -after Authors