As per section 206AA, a declaration in Form No. 15G or Form No. 15H is not a valid declaration, if it does not contain PAN of the person making the declaration. If the declaration is without the PAN, then tax is to be deducted at higher of following rates :
At the rate specified in the relevant provision of the Act.
At the rate or rates in force, i.e., the rate prescribed in the Finance Act.
At the rate of 20%.