January 31, 2023 Self-assessment deadline If you need to file a self-assessment tax return, the filing deadline line is by 31 Jan 2023. The income tax payment is also due on the same date.
July 31, 2023 Second Payment on Account If you paid personal tax of more than £1,000 for the tax year April 2022, you might paid your first payment on account already. 31 July 2023 is the deadline to pay the second payment on account.