Bakers are being urged to beat the New Year rush and file their tax return before 31 January or face a £100 fine.

Self assessment tax returns have to be filed online at hmrc.gov.uk/online/index.htm and, if submitting it electronically for the first time, companies will need to register; an activation code can take up to seven working days to arrive.

The self assessment online service is available 24 hours a day, with the quietest time to use it between 5pm and 8am, Monday to Friday. You will need to provide details of business accounts for the tax year ended 5 April 2010, such as spreadsheets of income and expenditure, bank and credit card statements, and invoices from customers and expenses receipts. Details of any other income, such as interest on bank and building society accounts or income from stocks and shares, need to be given too.

Visit hmrc.gov.uk/sa or call the self assessment helpline on 0845 900 0444.