CIS return
Construction Industry Scheme: monthly return due for period up to 5th of previous tax month.
Self-assessment deadline (payment on account)
Deadline for first self-assessment payment on account for tax year ended 5 April 2018.
Self-assessment deadline (balancing payments)
Deadline for online submission of self-assessment balancing payments for 2017/18 tax year.
Self-assessment deadline (online)
Deadline for online submission of self-assessment tax return for 2017/18 tax year.
Corporation tax payment
Corporation tax payment due for year end 30 April 2018, for those companies not liable to pay their liability by instalments.