The data provide a quantitative measure of the dry bulk density, soil texture, organic matter content (LOI) and organic carbon present within surface soils (up to a depth of 10 cm). A total of 212 samples from 49 sites across England and Wales were collected using modified syringe samplers as part of the citizen scientist programme CarbonQuest, part of Carbon Storage in Intertidal Environments (C-SIDE) project. Sites were chosen to represent contrasting habitats across England and Wales, in particular sediment types, vegetation and sea level history.The samples were processed for bulk density, soil texture, organic matter content using the Loss on Ignition (LOI) method and the organic carbon was quantified through elemental analysis. The data were collected to help create a detailed picture of saltmarsh carbon storage in surficial soils across England and Wales. The work was carried out under the NERC programme - Carbon Storage in Intertidal Environment (C-SIDE), NERC grant reference NE/R010846/1 Full details about this dataset can be found at https://doi.org/10.5285/e5554b83-910f-4030-8f4e-81967dc7047c