If a tax return is issued you have a legal liability to fill the thing in. If not you will have a 100 penalty issued. Those individuals who complete returns using software are sent a notice advising them that a tax return is due. If a taxpayer is not issued with a tax return but has tax due they should notify HMRC who may then issue a return.Preparing a tax return is one of those things we tend to build up in our minds as a big deal, when it doesn't have to be. It's like painting the living room. Prepare and lodge your own tax return electronically.

A tax return is sometimes required for other reasons, for example to check if the correct tax has been paid overall. So if you are sent a tax return, you must fill it in and send it back even if you believe that you have no extra tax to pay. A tax return is a document filed with HMRC that declares a taxpayers liability for being taxed, based on their yearly income. Three outcomes are possible from filing a tax return: either the taxpayer has either been charged too much or too little for their income, or they have been charged the correct amount. A tax return is a form on which you are asked to report your income and capital gains, and give details of reliefs and allowances claimed, for a particular tax year. The tax year runs from 6 April to 5 April, and the tax return covering the year ended 5 April 2008 is sometimes called the 2008 tax return', or the return for 2007/08.It applies to taxpayers who are identified as requiring a tax return and who are issued with a notice to file or a paper self assessment tax Return incorporating a notice to file. It also applies to people who make a claim outside a tax return. If you are newly self-employed it is not enough simply to file a tax return by October 31 for the tax year in which you became self-employed. You must tell HMRC that you have started to work for yourself within three months of doing so - you face a fine of 100 if you don't. Further, at death, the executor of your estate must also file an Estate Tax return.

HMRC have 12 months from the date of filing the return in which to open an enquiry, provided that the tax return is submitted by the applicable deadline for the method used. If a return is submitted after the deadline for that method, HMRC have up to and until the quarter day following the first anniversary of the date the return was filed, in which to open an enquiry. HMRC may sometimes refer to such cases as investigations, in order to distinguish them from enquiries pursued under the S9A powers. In such cases HMRC have to rely on the information powers in TMA70/S20 to support the investigation or seek a Regulation 10 notice (General Commissioners (Jurisdiction and Procedure) Regulations 1994 SI1994/1812) from the Commissioners in an appeal hearing. HMRC's local office structure has been dismantled but the new structures do not appear to provide adequate support mechanisms. There is little doubt that this issue is the biggest single cause for concern among tax technicians and accountants, who represent the largest number of qualified tax advisers in the UK, many of whom deal with HMRC on a very regular basis.

Remember that if you do file your tax return on time and do not breach rules you are far less likely to attract the attention of the HMRC investigators.