Tax return deadline: HMRC answers your questions
Well over a million people have yet to submit their tax returns to HM Revenue and Customs (HMRC), although the deadline is 31 January.
The forms must be completed by self-employed people and those with one source of income - but also by high earners who claim child benefit.
People who miss the deadline face a £100 fine, but may be allowed an extension if they have registered to file online.
BBC Breakfast put viewers' questions to HMRC director general of personal tax Ruth Owen.