A hydratable concentrated surfactant composition comprising: a) from 30 to 50 wt % of anionic surfactant selected from sodium laureth ether sulphate, sodium pareth ether sulphate and mixtures thereof, by weight based on the total weight of the composition; b) from 4 to 12 wt %, of a co-surfactant, which is selected from a betaine, cocamide monoethanolamide and mixtures thereof, based on the total weight of the hydratable concentrated surfactant composition; c) from 0.2 to 3 wt %, by weight of the total composition, of sodium benzoate; d) an additional phase modifier selected from nonionic esters comprising a carbon chain having a carbon chain length of C8 - C12, selected from octyl acetate, decyl acetate, dodecyl acetate and mixtures thereof, preferably decyl acetate; e) from 0.2 to 3 wt % of a viscosity modifier, by weight of the total composition, which is an inorganic electrolyte; f) from 10 to 60 % by weight water by weight of the total composition; wherein the surfactants are in a lamellar phase; and wherein the hydratable concentrated surfactant composition has a pH of from 3 to 6; and wherein the hydratable concentrated surfactant composition has a viscosity of from 8,000 to 200,000 mPas -1 (cps), when measured at 30°C on a Brookfield DV2T using a Spindle RV-05 at 20 rpm for 60 seconds on a Helipath stand; and wherein the weight ratio of a) the anionic surfactant to b) the co- surfactant is from 3:1 to 10:1. wherein the weight ratio of sodium benzoate (c) to total surfactant (a) + (b) is 1:5 to 1: 75, preferably from 1:10 to 1:65, more preferably 1:15 to 1:50, most preferably 1:35. a) from 30 to 50 wt % of anionic surfactant selected from sodium laureth ether sulphate, sodium pareth ether sulphate and mixtures thereof, by weight based on the total weight of the composition; b) from 4 to 12 wt %, of a co-surfactant, which is selected from a betaine, cocamide monoethanolamide and mixtures thereof, based on the total weight of the hydratable concentrated surfactant composition; c) from 0.2 to 3 wt %, by weight of the total composition, of sodium benzoate; d) an additional phase modifier selected from nonionic esters comprising a carbon chain having a carbon chain length of C8 - C12, selected from octyl acetate, decyl acetate, dodecyl acetate and mixtures thereof, preferably decyl acetate; e) from 0.2 to 3 wt % of a viscosity modifier, by weight of the total composition, which is an inorganic electrolyte; f) from 10 to 60 % by weight water by weight of the total composition; wherein the surfactants are in a lamellar phase; and wherein the hydratable concentrated surfactant composition has a pH of from 3 to 6; and wherein the hydratable concentrated surfactant composition has a viscosity of from 8,000 to 200,000 mPas -1 (cps), when measured at 30°C on a Brookfield DV2T using a Spindle RV-05 at 20 rpm for 60 seconds on a Helipath stand; and wherein the weight ratio of a) the anionic surfactant to b) the co- surfactant is from 3:1 to 10:1. wherein the weight ratio of sodium benzoate (c) to total surfactant (a) + (b) is 1:5 to 1: 75, preferably from 1:10 to 1:65, more preferably 1:15 to 1:50, most preferably 1:35. wherein the surfactants are in a lamellar phase; and wherein the hydratable concentrated surfactant composition has a pH of from 3 to 6; and wherein the hydratable concentrated surfactant composition has a viscosity of from 8,000 to 200,000 mPas -1 (cps), when measured at 30°C on a Brookfield DV2T using a Spindle RV-05 at 20 rpm for 60 seconds on a Helipath stand; and wherein the weight ratio of a) the anionic surfactant to b) the co- surfactant is from 3:1 to 10:1. wherein the weight ratio of sodium benzoate (c) to total surfactant (a) + (b) is 1:5 to 1: 75, preferably from 1:10 to 1:65, more preferably 1:15 to 1:50, most preferably 1:35.