fixity armless

Hello! I moved to the UK in the end of 2022. In September 2023 I received P800 form that I underpaid £460.80 tax for company benefits in the year ending in 2023. I opted in for taking that money from future taxes. In the 2023-2024 year I had tax code 0T. In current tax year I have tax code starting from K with an explanation of underpaid 460.80 pounds. I now fill in self-assessment form for 2023-2024 and stuck in the "underpaid tax included in PAYE" coding. Should I put "0" in the "amount of underpaid tax for earlier years included in your tax code for 2023-24" since PAYE code is equal to 0T? Or should I put 460.80 here because of P800?

Thank you for the response! In order to correctly calculate capital gains tax, what price should I use to estimate initial value of the assets? Should I use the price at vesting date? If selling price less then the initial price, can I report capital gain loss?

Hello! I moved to the UK a year ago. During my previous employment I was awarded with RSU of non-UK company listed in the US for the work outside of the UK. The vesting date of the RSU is before arrival to the UK. The employer hasn't payed any taxes in accordance to the tax laws in the country of residence. The trade of the company was halted on the market and thus I was not able to exercise or sell RSU before moving to the UK. My question is, once I am able to exercise (and receive shares) or exercise-and-sell my RSU, what taxes should I pay in the UK? How do I fill my set assessment form?