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Hi, I'm filling out my first Self Assessment and when I go to the "View Calculation" screen it is stating that my personal allowance for 23-24 was £12750. However during that year I received a letter from the HMRC saying that my personal allowance was being reduced and I finished the year with a Tax Code of 640L M1. This year I'm currently on 835L. The only reason I'm filling in a Tax return this year is that I went over 10K for interest earnings. I'm new to this but it appears the calculation for what I owe is based on me having the the full personal allowance available for PAYE but that wasn't the case. Am I getting this completely wrong? I thought the whole point in me having a reduced Personal Allowance was to proactively pay some of the additional tax. Thanks