Abstract: There is a disclosed composition suitable for use in a process for electroplating surfaces with tin, comprising: a) one or more acids selected from sulphuric acid, sulphamic acid, aryl sulphonic acids, alkyl sulphonic acids and alkanol sulphonic acids, b) one or more addition agents comprising a mono-, di- or tri-substituted phenol (each optionally alkyoxylated) or a mixture of two or more such compounds, in which at least one of the substituents includes a secondary, tertiary or quaternary nitrogen atom, c) a tin source and d) water. There is also disclosed a method of tin plating using the composition of this invention.