I am a bookkeeping for a cis client. His return was sent in by me with incorrect figures on. HMRC have got in touch and I have agreed that there figures from his contractors are correct. This made his gross about £5000 short. However the amount of tax @ 20% that was paid will be about right. The only difference should be more ni.
The HMRC have said that there may be a penalty. This was a couple of days ago they haven't been back to me yet.
Has anyone been in this position themselves to advice me what I can expect to happen.