Am being asked to pay money for 2022/23 as part of my 2021/22 return

Hello, nb. this is my first time filling in a self assessment. I have just finished my online self-assessment for my side job for the 2021/22 tax year - I need to pay £1,600 tax on this by 31/01/2023. However the View Your Calculation page then includes the line "1st payment on account for 2022-23 due 31 January 2023 - £690" followed by "Total due by 31 January 2023 - £2,290", with a note saying "2nd payment of £690.70 due 31 July 2023." I'm a bit confused - I assume this extra £690 is an early estimate for part of the 2022/23 tax year, based on my earnings from 2021/22? I thought that each tax year is kept separate? The figures provided for 2021/22 are based on precise actual income received. I don't understand why I'll need to pay tax upfront for 2022/23 and then spend time recalculating it next year for over/underpayment..?? Surely it would just make more sense for me to pay my £1,600 now, then provide a new and accurate return for 2022/23 in Jan 2024, and pay the actual tax owed then? Please can you clarify? sincerely, DM

Hi,

You are being asked to pay Payments on Account which are mandatory if you meet the conditons.

Understand your Self Assessment tax bill

Thank you.