31 January - for tax year ended 5 April the previous year

This is the deadline for online returns and is also the deadline for payment of tax if applicable. If the liability is over £1,000, a payment on account will be due.

31 July - 2nd payment on account due if applicable.

Corporation Tax, for limited companies, is due 9 months and one day after the end of the accounting period. For example, if the accounting period ends on 31 March, Corporation Tax is due on or before 1 January the following year.