1* Annual corporation tax due for companies with year ending nine months and a day previously, eg tax due 1 May 2009 for year ending 31 July 2008.
14* Quarterly instalment of corporation tax due for large companies (depending on accounting year end).
19* Pay PAYE/NIC and CIS deductions for period ending 5th of the month if not paying electronically. Submit CIS monthly return.
22* PAYE/NIC and CIS deductions paid electronically should have cleared into HMRC bank account.
30/31 Submit CT600 for year ending 12 months previously (28 February 2010 for February 2009 year end). Last day to amend CT600 for year ending 24 months previously.
*If the due date for payment falls on a weekend or bank holiday, payment must be made by the previous working day.

May 2009
3  Submit forms P46 (car) for quarter to 5 April 2009.
19  File 2008/09 end of year PAYE forms (P35 and P14s).
(Penalties may be charged if forms are late and are automatic from 26 May 2009.)
31  Last date to issue 2008/09 P60s to employees.

July 2009
5  Final date to agree 2008/09 PAYE Settlement Agreements.
6  Last date for returns of expenses and benefits (forms P11D, P11D(b) and P9D) for 2008/09 to reach HMRC. Relevant employees to receive copies of forms P11D and P9D.
Last date to submit annual returns for employee share schemes and employment-related securities for 2008/09 (forms 34, 35, 39, 40 and 42).
14  Due date for CT61 return and payment for quarter to 30 June 2009.
19  Due date for Class 1A NICs (22nd if paid electronically). 31 Due date for second payment on account of 2008/09income tax and Class 4 NIC.
Last day to pay 2007/08 tax to avoid second automatic 5% surcharge (unless late payment agreed with HMRC) and to file 2007/08 tax return to avoid second automatic penalty up to £100.
Confirm tax credit claims for 2008/09.

August 2009
2  Submit forms P46 (car) for quarter to 5 July 2009.

October 2009
5  Deadline to notify HMRC of chargeability to income tax or CGT
for 2008/09.
14  Due date for CT61 return and payment for quarter to 30 September 2009.
19  Due date for tax and NICs under PSA.
31  Deadline to submit 2008/09 self-assessment tax return if filed on paper (up to £100 penalty if late).

November 2009
2  Submit forms P46 (car) for quarter to 5 October 2009.

December 2009
30  Last day to submit 2008/09 tax return online to have unpaid tax of up to £2,000 collected through the 2010/11 PAYE code.

January 2010
1   VAT standard rate to return to 17.5%.
14   Due date for CT61 return and payment for quarter to 31 December 2009.
31  Submit 2008/09 self-assessment return electronically (up to £100 penalty if late). Pay balance of 2008/09 income tax and CGT plus first payment on account for 2009/10.

March 2010
31  Last-minute planning for 2009/10. Last few days to use any CGT and inheritance tax annual allowances and exemptions.