This note provides details on how to calculate quarterly instalment payments (QIPs) for large and very large companies.

The instalment amounts are based on the estimated corporation tax liability of the company’s current accounting period. Large and very large companies are required to forecast their tax liabilities for a tax accounting period to work out instalment payments. Forecasting accurately will help avoid interest charges on underpayments. Since 1 April 2019, very large companies need to forecast early during the accounting period because their instalment payments must all be paid before the end of the accounting period.

For general details regarding QIPs and determining whether a company is large or very large for this purpose, please refer to the QIPs ― when do they apply? guidance note.