Tax Calendar

January: Your UK Return for the prior year should be filed by 31 January. Late filing may give rise to penalties.
Interest starts to accrue on any UK tax which remains outstanding at 31 January.
First payment on account of UK tax for the current tax year should be made by 31 January to avoid an interest charge.
The final US estimated payment for the previous calendar year is due 15 January.
February: If you wish to claim exemption from US withholding on your earnings for the current year you must file Form W-4 by 15 February.
If your UK Return is still outstanding at 28 February and tax is unpaid, a 5% tax penalty will be charged.
Return your completed US questionnaire by 1 March to ensure we can prepare the Return by 15 April.
March: The due date for calendar year corporation income tax returns is 15 March.
Consider making UK pension payments to use up the current year allowance before 5 April.
April: US tax return for prior calendar year due 15 April for US resident tax payers. Late filing may give rise to penalties.
Interest starts to accrue on any US tax which remains outstanding at 15 April.
Was your prior year liability greater than $1,000? First estimated tax payment due for US resident taxpayers for the current calendar year in order to minimise estimated tax penalties.
Even though you live outside the US and have an automatic extension to 15 June you may still need to file a state extension request by 15 April.
May: Form P35, year end PAYE summary is due by 19 May.
Form P60, reporting annual earnings must be distributed to employees.
June: If you live outside the US and you have not yet filed your US tax return, you need a further extension of time to file your Return beyond 15 June.
Non US residents with US taxable income not subject to withholding should file their Return or their extension application by June 15.
The second estimated payment of the year is due on 15 June. (First estimated payment for nonresident aliens not subject to withholding)
30 June deadline for filing reports of foreign bank accounts in which an interest was held in the previous calendar year. These forms need to be filed by all US citizens and green card holders who held an interest in accounts having an aggregate balance of $10,000 at any point during the year. There is no extension available and penalties apply.
July: National Insurance Contributions on UK benefits should be paid by the employer by 19 July.
Second payment on account of UK tax should be made by 31 July to avoid an interest charge.
UK Tax still outstanding for the prior year by 31 July will suffer a further 5% penalty charge.
August: Consider whether you require a further extension of time to file your Return beyond 15 August.
Due dates for payment of UK corporation tax for calendar year corporations.
September: The third estimated payment of the year is due 15 September (Second for nonresident aliens).
Return your completed UK questionnaire by 30 September to ensure we can guarantee filing your UK Return by 31 January following.
October: Companies House filing for calendar year UK corporations required by 31 October.
December: The IRS will not grant an extension to file your Return beyond 15 December. Act immediately.
Those who claim foreign tax credits in the US on a paid basis should consider paying UK Taxes, otherwise due by 31 January following, before the end of the calendar year to maximise available tax credits on calendar year US tax return.
Due date for UK corporation self assessment return with calendar year end 31 December.