There is an advance clearance procedure. It is not mandatory for companies to apply for clearance. The procedure exists so commercial decisions are not hindered by uncertainty about the possible application of the anti-avoidance provisions. For practical reasons only the company whose shares or debentures are being acquired or the company making the acquisition can apply for clearance. TCGA92/S138 allows either of these companies to apply to the Board for confirmation that the anti-avoidance provisions of TCGA92/S137 will not prevent TCGA92/S135 from applying. For the clearance to be valid the application must be made and dealt with before the new shares or debentures are issued.