A fast screening method to estimate PV hosting capacity in a low voltage grid with respect to overvoltage and transformer overload is presented in this paper. The method uses the resistance of the direct path from the slack bus to customer and an assumed topology in order to avoid complete knowledge about the grid topology. Using an assumed topology an estimate of the minimum overvoltage hosting capacity is obtained for each penetration level and the transformer overload hosting capacity for any combination of customers having PV. The method is suitable for initial response to demand connection enquiries and showed good correspondence by comparison with power flow simulation using the actual grid topology. The method was implemented on four semi-rural low voltage grids and the results showed that these grids were able to handle PV infeed comparable to maximum winter load due to three-phase connections.