The deadlines for submitting your Company Tax return are relatively straight forward; likewise for paying the Corporation Tax due. The due date for submitting the Corporation Tax return is one year after the financial year end. The due date for the payment of Corporation Tax is nine months after the year end.
Companies are generally not tied to the typical fiscal period that end on 5th April, and a company can generally choose what year end they wish to have. It is quite common for companies to choose a year end of 31st March which helps the directors and accountants devise Corporation and Personal Tax strategies. For companies with a 31st March year end, the Corporation Tax is due 31st March the next year and the Company Tax is required to be settled by 31st December.
Likewise with most Self Assessment Tax Returns, penalties apply for late submission and payment, see below for more details.