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Issue of Self Assessment tax returns

Soon after each new tax year (6 April) HMRC sends a tax return or Notice to Complete a Tax Return (SA316) for the previous tax year to everyone who normally completes one.

• More about who needs to complete a tax return

Key filing dates for tax returns

Date	Why this deadline is important
31 January	This is the formal deadline for sending back a tax return . If it arrives after this deadline you'll be charged an automatic £100 penalty.
31 October	Paper tax returns for the tax year that ended on the previous 5 April must reach the HMRC by this date if you want them to: calculate your tax for you tell you what to pay by the following 31 January collect tax through your tax code (if possible) where you owe less than £2,000 If they receive your paper tax return after 31 October and process it by 30 December, they'll still calculate your tax and try to collect tax through your tax code; but they can't guarantee to tell you what to pay by 31 January. If you file your tax return online the deadline is later (see below) because the system calculates your tax liability for you automatically on-screen.
29 December	If your agent submits your tax return via Electronic Lodgement Service (ELS) you must send it back by this date if you want HMRC to collect tax through your tax code (if possible) where you owe less than £2,000.
30 December	If you file your tax return online you must send it back by this date if you want HMRC to collect tax through your tax code (if possible) where you owe less than £2,000. Otherwise you can file up to 31 January.

Key Self Assessment payment dates

Key dates	What payments or penalties are due?
31 January	If you were sent a tax return by the previous 31 October this is the deadline for paying the balance of any tax you owe. This is referred to as the 'balancing payment'. HMRC will charge you daily interest after this date, until it receives your payment. This is also the date by which you must make any first 'payment on account' for the current tax year. For example, on 31 January 2009 you will have to pay both of the following: the balance of tax owing for the year 2007-2008 the first 'payment on account' for 2008-2009
28 February	If you don't pay the balancing payment by 31 January, you'll be charged an automatic 5% surcharge on top of the amount still owing. This is in addition to any interest payments
31 July	This is the deadline for making a second 'payment on account' for tax owing for the preceding tax year. If you still owe tax that you were due to pay by the previous 31 January, you'll be charged a second automatic 5% surcharge on top of the amount you owe.

Tax returns received after 31 October

If you received your tax return after 31 October, your Tax Office will tell you the latest payment dates for any tax you owe. As a rule you have 30 days from the date on the request for payment (called the 'Statement of Account').

Payments on account

You'll be asked to make two 'payments on account' for the current tax year if you don't pay tax through the Pay As You Earn (PAYE) system and your tax bill for the previous year was over £500. Each payment on account equals one half of the previous year's tax liability.

If you expect your income for the current year to be significantly different from the previous year you can ask for these payments to be adjusted.

• More about payments on account

More useful links

• Appeals against HM Revenue & Customs decisions
• How to act on behalf of another taxpayer