ConfusedCodger

Hi, I opened a Santander 2 year fixed rate ISA and on 29th March 2023, so tax year 2022/23. in which I put the full £20,000 allowance. On 6th April 2023, I paid the full £20,000 into the same ISA account, so tax year 2023/24. On 2nd April ‘23 I received £6.90 interest, then on 2nd April ‘24 I received £1,672.24 interest, which I believe is £800ish for each £20,000 amount @ 4.2% interest. I expect to get another £1,672 ish payment on 2nd April 2025 next week, so £800ish per year, per £20,000 over the 2 year fixed. So I used my annual ISA allowance for 2022/23 + 2023/24 but don’t have any further money to invest. As the first £20,000 was put in a 2 year fixed in the 2022/23 tax year did that technically have 2 years to April 2024 or is it April 2025? I need to know if I can transfer £20,000 from Santander into a new cash ISA for the 2024/25 tax year as I have not used any of the £20,000 allowance? I obviously only have days now to potentially do this/ I’ve had a letter about my 2 year fixed rate ISA maturing on 1st April 2025 so I plan to open a new cash isa to transfer £20,000 to use my full allowance for the 2025/26 tax year. Is this ok to do or have I got this all wrong?