Corporation Tax Self-Assessment

All organisations liable to corporation tax (mostly limited companies) are obliged to undertake self-assessment. Within twelve months of the end of an accounting period a detailed return must be filed together with the tax due.

The return must include liabilities of close companies on loans and advances to shareholders and others, and of liabilities of controlled foreign companies. Companies conducting international business must also self-assess under transfer pricing legislation.

A legal charge is created by filing a return, without further action by the Inland Revenue.

The Inland Revenue has a fixed period of twelve months to decide to enquire into the return. Finality comes by the passage of time, or following the formal closure of an enquiry.

Companies whose profits exceed £1.5m annually will have to make Quarterly Instalment Payments of tax, starting six and a half months into the accounting period.

Companies cannot opt for Inland Revenue calculation of their tax.

The due date for payment of corporation tax is nine months and one day after the end of the accounting period (subject to the Quarterly Instalment Payment regime for large companies).

Companies that are chargeable to tax for an accounting period but do not receive a Notice to file a return must give notice to the Inland Revenue that they are chargeable. The notice must be given within 12 months from the end of the accounting period.