The dataset details global positioning system (GPS) locations and elevations recorded for 1323 sampling sites across UK saltmarshes. Between 2018 and 2021, soil was sampled at 1323 locations as part of the Carbon Storage in Intertidal Environments (C-SIDE) project to facilitate the calculation of saltmarsh soil organic carbon stocks and burial rates. Sites were chosen to represent contrasting habitat types in the UK, in particular sediment types, vegetation and sea level history. The work was carried out under the NERC programme - Carbon Storage in Intertidal Environment (C-SIDE), NERC grant reference NE/R010846/1.