To avoid Frontier's cancellation fee ＋𝟏－𝟖𝟑𝟖－𝟑𝟎𝟎－𝟑𝟖𝟑𝟎 [𝐎𝐓𝐀] or ＋𝟏－𝟖𝟑𝟖_𝟑𝟎𝟐－𝟑𝟖'𝟑𝟎 𝐔𝐊 (𝐎𝐓𝐀), cancel within 24 hours or booking or ensure your flight is at least 7 days away.