We examined the use of delta super(13)C, TOC and C/N geochemistry of sedimentary organic matter to reconstruct former sea levels and paleoenvironments in the absence of suitable microfossil data. The modern distribution of delta super(13)C, TOC and C/N of 33 vegetation and 74 surface sediment samples collected from four coastal wetlands in the Thames Estuary and Norfolk, UK are described. The delta super(13)C, TOC and C/N geochemistry of sediments varied in relation to the input of in situ vascular vegetation versus allochthonous particulate organic matter and algae, which was controlled primarily by tidal inundation. We reviewed published and unpublished studies to produce an English database of vegetation (n=257) and sediment (n=132) delta super(13)C, TOC and C/N geochemistry. Four elevation-dependent environments in the database had statistically distinct delta super(13)C, TOC and C/N values: (1) tidal flat/low marsh ( delta super(13)C: -24.9 plus or minus 1.2ppt; TOC: 3.6 plus or minus 1.7%; C/N: 9.9 plus or minus 0.8); (2) middle marsh/high ( delta super(13)C: -26.2 plus or minus 1.0ppt; TOC: 9.8 plus or minus 6.7%; C/N: 12.1 plus or minus 1.8); (3) reed swamp ( delta super(13)C: -27.9 plus or minus 0.7ppt: TOC: 36.5 plus or minus 11.5%; C/N: 13.9 plus or minus 1.2); and (4) fen carr ( delta super(13)C: -29.0 plus or minus 0.6ppt; TOC: 41.6 plus or minus 5.7%; C/N: 17.4 plus or minus 3.1). The delta super(13)C, TOC and C/N geochemistry database was applied to a Holocene sediment core collected from the Thames Estuary to produce three new sea-level index points and one limiting date, illustrating the utility of delta super(13)C, TOC and C/N values to reconstruct Holocene relative sea levels.