6th
Pre-Owned Assets Tax rules become operative. Revised tax regime for trusts begins. Investment limit for stocks and shares mini-ISA rises to £4,000 and separate ISA insurance component consolidated into stocks and shares component. Child Trust Fund starts for children born after 31 August 2002. Start of final year of existing pension tax regime. National minimum wage 'fair' piece rate rises by 20%.

14th
Instalment of corporation tax due for large companies with accounting periods ended: 31 December 2004, 31 March 2005, 30 June 2005 and 30 September 2005.

19th
Tax and NIC due on IR35 deemed salary for 2004/05. PAYE & NIC due for month to 5 April 2005, and 4th quarter 2004/05.

29th
IHT due on any lifetime transfers made between 6 April 2004 and 30 September 2004. Due date is 30 April, but this is a Saturday.

3rd
Submit forms P46 (car) for quarter ended 5 April 2005.

19th
File CIS forms, and P60, P35 and P14 for 2004/05. PAYE and NIC due for month ended 5 May 2005.

26th
Final deadline for filing forms P14 and P35 after seven day grace period under ESC B46.

31st
Issue employees with copies of forms P60 for 2004/05.

17th
PAYE and NIC due for month to 5 June 2005. Due date is 19 June, but this is a Sunday.

30th
Submit CT600 return for year ended 30 June 2004. File accounts at Companies House for private companies with year ended 31 August 2004 and public companies with year ended 30 November 2004.

5th
Last day to reach PAYE settlement agreement for 2004/05. Close companies to elect for all beneficial loans to a director to be treated as a single loan.

6th
File forms P11D and P9D with the Inland Revenue and give copies to employees. File forms P11D (b) to return class 1A NIC due for 2004/05. File share scheme returns (form 42) for 2004/05.

14th
Instalment of corporation tax due for large companies with accounting periods ended: 31 March 2005, 30 June 2005, 30 September 2005 and 31 December 2005.

19th
PAYE and NIC due for month to 5 July 2005 and for 1st quarter 2005/06. Class 1A NIC due for 2004/05.

29th
File accounts at Companies House for private companies with year ended 30 September 2004. File accounts at Companies House for public companies with year ended 31 December 2004. Second payment on account of income tax due for 2004/05. Automatic fine of further £100 (or tax outstanding, if less) for all 2003/04 tax returns still not submitted. 5% surcharge on unpaid income tax and CGT due for 2003/04. Due date is 31 July, but this is a Sunday.

2nd
Submit forms P46 (car) for quarter ended 5 July 2005.

19th
PAYE and NIC due for month to 5 August 2005.

31st
File accounts at Companies House for private companies with year ended 31 October 2004 and public companies with year ended 31 January 2005.

19th
PAYE and NIC due for month to 5 September 2005.

30th
Personal tax return for 2004/05 must be submitted if Inland Revenue is to complete the tax calculation. CT due for small and medium sized companies with accounting periods ended 31 December 2004. Due date is 1 October, but this is a Saturday.

1st
National minimum wage increases.

5th
Individuals must inform Inland Revenue of new sources of income or gains if no tax return received for 2004/05.

14th
Instalment of corporation tax due for large companies with accounting periods ended: 30 June 2005, 30 September 2005, 31 December 2005 and 31 March 2006.

19th
Tax and class 1B NIC due under PAYE settlement agreements for 2004/05. PAYE and NIC due for month to 5 October 2005 and 2nd quarter 2005/06.

31st
Last day to ask Inland Revenue for a self assessment tax return for 1999/2000. File accounts at Companies House for private companies with year ended 31 December 2004 and public companies with year ended 31 March 2005.

2nd
Submit forms P46 (car) for quarter ended 5 October 2005.

18th
PAYE and NIC due for month to 5 November 2005. Due date is 19 November, but this is a Saturday.

30th
Last day to apply for special PAYE arrangement for overseas employees. File accounts at Companies House for private companies with year ended 31 January 2005 and public companies with year ended 30 April 2005.

19th
PAYE and NIC due for month to 5 December 2005.

28th
File accounts at Companies House for private companies with year ended 28 February 2005.

30th
Claim repayment of class 2 NIC for 2004/05 because of low earnings. Last chance to amend CTSA return for year ended 31 December 2003. Submit CT600 return for year ended 31 December 2004. File accounts at Companies House for public companies with year ended 31 May 2005. Last day to submit personal tax return for 2004/05 by Internet if tax due of up to £2,000 is to be included in the 2006/07 PAYE code.
Due date is 31 December, but this is a Saturday.

The Inland Revenue must receive electronic PAYE/NIC payments by 22nd of every month or the previous working day if the 22nd is not a working day.

1st
Corporation tax due for small and medium sized companies with accounting periods ended 31 March 2005.

14th
Instalment of corporation tax due for large companies with accounting periods ended: 30 September 2005, 31 December 2005, 31 March 2006 and 30 June 2006.

19th
PAYE and NIC due for month to 5 January 2006, and for 3rd quarter 2005/06.

31st
Final income tax payment and CGT due for 2004/05 plus first payment on account of income tax for 2005/06. Submit personal tax return for 2004/05, or receive automatic fine of £100 (or unpaid tax, if less). Final date for personal pension contribution to be made with an election to backdate to 2004/05.

2nd
Submit forms P46 (car) for quarter ended 5 January 2006.

14th
Last day to defer Class 1 NICs for 2006/07.

17th
PAYE and NIC due for month to 5 February 2006. Due date is 19 February, but this is a Sunday.

28th
5% surcharge on any unpaid income tax and CGT due for 2004/05.

17th
PAYE and NIC due for month to 5 March 2006. Due date is 19 March, but this is a Sunday.

31st
Submit CT600 return for year ended 31 March 2005.

5th
Deadline for paying into ISA for 2005/06. Last chance to make gifts to use IHT exemption for 2005/06 or to make gains to use CGT exemption for 2005/06. Valuation day for pension benefits and last day to make pension contributions before the start of the simplified pension tax regime on 6 April 2006.