We generalise the familiar notions of invariant basis number, rank condition, stable finiteness and strong rank condition from rings to modules. We study the inter relationship between these properties, identify various classes of modules possessing these properties and investigate the effect of many standard module theoretic operations on each one of these properties. We also tackle the important problem of preservation or non-preservation of these properties when we pass respectively to the module of polynomials, power series or inverse polynomials.