514. Tax payments; due date, assessments and excessive payments.

A tax payment1, including any reduced tax payment2, whether any deduction out of a connected payment3 or provision in respect of a connected transfer4 has been made or not, is due at the time by which the return5 is to be made (referred to as 'the due date') and payment must be made before, or at the time when, that return is made6. A payment at any time so due is payable by the person who makes the connected payment or transfer concerned, without the making of any assessment in respect of it7. Tax which has become due and