Pat the fish fillets dry with paper towels.
In a mixing bowl, combine flour, baking powder, salt, and pepper.
Gradually whisk in the beer until smooth.
Heat vegetable oil in a deep frying pan to 350°F (175°C).
Dip each fish fillet into the batter, ensuring it's well coated.
Carefully place the battered fish into the hot oil.
Fry until golden brown, about 4-5 minutes per side.
Remove fish and drain on paper towels.
Serve hot with lemon wedges and tartar sauce.