If you were sent a 2011/12 tax return, this is the deadline for sending back the completed return.
This is also the deadline for paying the balance of any tax that you owe for 2011/12. Some people may have to make "payments on account".
Each payment will normally equal one half of the previous year's tax liability (after taking off tax deducted at source and tax credits on dividends). The payments are due on 31 January in the tax year and 31 July following the tax year. Any Capital Gains Tax due for 2010/11 would be part of, or form, the balancing payment due on this date. If either the balancing payment for 2011/12 or first payment on account for 2012/13 is not made by this date, then interest will be charged.
If you were sent a tax return for 2011/12, you will be charged a penalty of £100 if HMRC has not received your return by this date.
If you have not made the balancing payment due for 2011/12 by this date, an automatic 5% surcharge will be applied. The 5% surcharge does not apply to late payment of the first payment on account for 2012/13.
The last day of the 2012/13 tax year.
The first day of the 2013/14 tax year.
By this date, your employer should have given you a Form P60 (pay and tax details from employment) to assist you with the completion of your tax return for the year ended 5 April 2013.
You must make a claim to HMRC for any new tax credits to which you are entitled (in order to receive full entitlement).
If applicable to you, your employer must provide you with a copy of Form P11D showing details of the benefits in kind provided to you or expense payments reimbursed to you. Benefits in kind include, for example, the provision of a company car.
Some people may have to make payments on account. Each payment will normally equal one half of the previous year's tax liability (after taking off tax deducted at source and tax credits on dividends). The payments are due on 31 January in the tax year and 31 July following the tax year. If you need to make a second payment on account for the tax year ending on 5 April 2013, this is the date by which it should be made. If you have still not made a balancing payment of tax for 2011/12 by this date, you will be charged a second automatic 5% surcharge. The second 5% surcharge does not apply to late payment of the first payment on account for 2012/13. If you were sent a tax return, for 2011/12 you will be charged a second penalty of £100 if HMRC has not received your return by this date.
You must tell HMRC of any income or capital gains you have received in the 2012/13 tax year, if you have not received a tax return. You have a legal obligation to do this. HMRC may, or may not, need to send you a tax return - some taxpayers will be able to pay the right amount of tax through an adjustment to their PAYE code.
If you were sent a 2012/13 tax return, this is the deadline for sending back the completed paper tax return. Paper tax returns must be filed by this date if you want HMRC to collect any unpaid tax (of under £2,000) for 2012/13 through PAYE. For self assessment tax returns filed on-line the filing deadline is 31 January 2014.
For those with a tax liability of less than £2,000, if you file your self assessment tax return on-line by this date, the tax office will adjust your PAYE code (provided you are an employee) so that you can pay any tax due for 2012/13 over time through PAYE, rather than as a lump sum on 31 January 2014.