The dataset details surface elevation and sedimentation measurements across five UK saltmarsh sites. Two of the sites were in Morecambe Bay, North West England and three of the sites were in Essex, South East England, each of these sites consisted of a saltmarsh area and adjacent mudflat area. Rod Sedimentation-Erosion Tables (rSETs) were installed at different distances from the vegetated margin. Three rSETs were deployed for each Essex site and four for the Morecambe sites. rSET benchmarks were installed with associated marker horizons to evaluate surface elevation changes and surface accretion respectively. This data was collected as part of Coastal Biodiversity and Ecosystem Service Sustainability (CBESS): NE/J015644/1. The project was funded with support from the Biodiversity and Ecosystem Service Sustainability (BESS) programme. BESS is a six-year programme (2011-2017) funded by the UK Natural Environment Research Council (NERC) and the Biotechnology and Biological Sciences Research Council (BBSRC) as part of the UK's Living with Environmental Change (LWEC) programme. Full details about this dataset can be found at https://doi.org/10.5285/b71f1244-3bc2-4b52-bf64-f3e479860e28