s 421JD Penalty if information not given correctly
(1) This section applies if a return under section 421JA, or any information accompanying such a return— (a) is given otherwise than in accordance with section 421JB, or (b) contains a material inaccuracy— (i) which is careless or deliberate, or (ii) which is not corrected as required by section 421JA(6). (2) The person in question is liable for a penalty of an amount decided by HMRC. (3) The penalty must not exceed £5,000. (4) For the purposes of subsection (1)(b)(i) an inaccuracy is careless if it is due to a failure by the person in question to take reasonable care.