The reactive power capability of wind generation (WG), producers can be used to provide volt/voltampere reactive (var) support in electrical distribution systems. In practice, the distribution network operator (DNO) is not able to dispatch reactive power-of all generators, and such units are referred to is noudispatchable generators. Then, the reactive power of these nondispatchable generators is nota defined value, and it should accomplish the limits settled by national grid codes. This paper addresses the optimal reactive power provision of nondispatchable WG units under a loss allocation strategy based on incremental generation use of the system (GUoS) tariffs. The optimization problem is set from generators' viewpoint aiming to find the re. active power provision that minimizes the loss charges subject to operational constraints. Optimal solutions are compared with the DNOs mandatory dispatches using a reactive optimal power flow tool. Two test systems are analyzed: a 10-kV 28 bus and 60-kV 55-bus. system throughout 672 and 168 h, respectively. The proposal permits to identify which units can be dispatched by the DNO due to its effect on the network.