A model for determining transport coefficients in the case of simultaneous heat, mass and momentum transfer in multicomponent boundary-layer flow along a flat interface has been delivered. The equations of the model were solved by the quasilinearisation technique. The practical utility and rapidity of the method is well illustrated. The computational studies of dimensionless transfer coefficients showed that the effects of multicomponent diffusion as well as injection caused by mass flux at the interface are not neglectable.