3. Border controls should be targeted and limited in scope, frequency, location and time, to what is strictly necessary to respond to the serious threat and to safeguard public policy and internal security. The Member State that carries out internal border control pursuant to the present Implementing Decision should regularly review the necessity, frequency, location and time of controls, adjust the controls to the level of the threat addressed, phasing them out wherever appropriate, and report to the Commission every two months. U.K.