Sift flour into a bowl. Season with salt and pepper. Using a fork, whisk milk and eggs together in a jug until combined. Pour over flour. Stir until smooth. Add corn and zucchini. Stir until well combined.
Add enough oil to a large non-stick fry pan to cover the base. Heat over medium heat until hot. Spoon 3 tbsps of mixture into pan, 3 fritters at a time. Cook for 3-4 minutes each side or until golden and firm to touch in the centre. Transfer to a wire rack to cool. Cover and repeat with remaining mix.