Introduction to this document

Self-assessment checklist

The tax return filing deadline is 31 January following the end of each tax year. Use our checklist to reduce the chances of making any errors.

Tax returns

Self-assessment is the current method of reporting your income and capital gains to HMRC each year. It is easy to make mistakes, especially if you are unable to file the return until near the deadline of 31 January. Common mistakes include:

  • missing income sources
  • missing capital gains
  • underclaiming tax reliefs
  • not reporting pension contributions or liability to the annual pension charge
  • believing the return to be filed when it isn’t successfully lodged with HMRC.

Making any of these errors can lead to penalties and/or interest. Use our Self-assessment Checklist to help ensure you’ve done everything to minimise errors.