Free One Tax Tool UK for 2025–2026. Estimates are for guidance only and not
financial
advice—please consult a professional.
MAIN DUE DATES FOR TAX PAYMENTS
Income tax, NICs and capital gains tax – Self
assessment
31 Jan in tax year Following 31 July
Normally 50% of previous year's income tax (less tax deducted at
source) and class 4 NICs
Following 31 Jan
Balance of income tax, class 4 NICs and CGT, plus class 2 NICs paid
voluntarily
Inheritance tax
On death:
Normally 6 months after end of month of death
Lifetime transfer 6 April–30 September:
30 April in following year
Lifetime transfer 1 October–5 April:
6 months after end of month of transfer
Capital gains tax – residential UK property
Report and pay within 60 days of completion of conveyance of the property
Corporation tax – Self assessment
9 months and 1 day after end of accounting period
Profits £1,500,000–£20,000,000: normally payable in 7th, 10th, 13th and 16th months
after start of the accounting period
Profits over £20,000,000: normally payable in 3rd, 6th, 9th and 12th months after
start of the accounting period
Growing companies: no instalments where profits are £10,000,000 or less and the
company was not a large company for the previous year.
2025/26 TAX CALENDAR
Make payment on previous working day where due date falls on a weekend/bank holiday.
Every month
19
Submit CIS contractors' monthly return.
22
PAYE/NICs/CIS deductions paid electronically for period ending 5th of
the month (19th if not paying electronically).
Month end
Submit CT600 for year ending 12 months previously.
Last day to amend CT600 for year ending 24 months previously.
April 2025
1
Residential SDLT threshold reverts to £125,000 with 2% rate then
applying up to £250,000. First-time buyer thresholds reduced by
£125,000.
6
Employers' NIC rate increased by 1.2% and secondary threshold lowered to
£5,000. Employment allowance per business increased to £10,500.
Increased voluntary class 2 and class 3 NIC rates. Car and van fuel
benefit and van benefit charges rise. CGT for carried interest increases
to 32%. CGT business asset disposal relief increased by 4%. National
minimum wage rates rise.
July 2025
5
Last date to agree a new PAYE Settlement Agreement (PSA) for 2024/25.
6
Deadline for employers to submit forms P11D (expenses) and P11D (b)
(benefits) for 2024/25 to HMRC and provide copies to employees.
22
Pay class 1A NICs (19 July if not paying electronically).
31
Confirm tax credit claims for 2024/25 and renewal for 2025/26. Second
payment on account for 2024/25 income tax and class 4 NICs.
August 2025
1
Penalty of 5% of the tax due or £300, whichever is the greater, where
the 2023/24 tax return has not been filed.
October 2025
5
Deadline to register for self assessment for 2024/25.
22
Pay tax and class 1B NICs on PSAs (19th if not paying electronically).
31
Deadline for 2024/25 tax return if filed on paper.
December 2025
30
Deadline to submit 2024/25 tax return online to have unpaid tax of up to
£3,000 collected through the 2026/27 tax code.
January 2026
31
Submit 2024/25 self assessment tax return online. Pay balance of 2024/25
income tax, class 4 NICs, CGT, class 2 NICs paid voluntarily plus first
payment on account for 2025/26 income tax and class 4 NICs.
February 2026
1
Initial penalty imposed where the 2024/25 tax return has not been filed
or has been filed on paper after 31 October 2025.
March 2026
3
First 5% penalty imposed on 2024/25 tax unpaid on 3 March.
April 2026
6
Making Tax Digital for Income Tax Self Assessment starts for
self-employed workers and landlords with qualifying income over £50,000.