First return obligations: newly registered taxpayers must report outward and inward supplies for the initial registration period. The provision requires newly registered taxable persons to file a first return reporting outward supplies from the date liability to registration began to the month-end of registration and inward supplies from the effective registration date to that month-end; composition taxpayers under section 8 must report until the quarter-end of registration. Sections 25, 26 and 27 apply mutatis mutandis to the first return, excluding provisions relating to the regular tax period.