A four‐terminal Hall resistance is analyzed using the Bu¨ttiker formalism of contacts. The possible maximum deviation of a quantized Hall resistance from ideal values in a multiterminal device is shown to be limited by the resistances of contacts. A general expression for the possible maximum deviation is derived for a multiterminal configuration with an arbitrary number of terminals in the condition of an arbitrary (integer) number of filled Landau levels. The influence of an inhomogeneous two‐dimensional electron gas on the Hall resistance is also discussed.