CTSA: the filing obligation: computations: in round thousands
Companies can submit tax computations rounded to the nearest £1,000 provided that they meet certain criteria. These criteria are set out in SP15/93.
Companies must continue to state amounts of group relief or relief for losses from other accounting periods in the actual sums surrendered, brought forward or carried back.
No rounding should take place on form CT600/CT200 itself, or in any arithmetic that precedes the entries made on that form.