Nusheen Hussain

Hi everyone My cash isa matured at the start of this month.I had 20,000 saved. And i received £1,000 interest at the end of its term. I transferred it to a new cash isa with a better rate and added 20,000 more for this years allowance. So as it stands i have 41,000 in total in my current cash isa for 2024/2025. Will i have to pay any tax on interest i receive at the end of its term as my balance is over 20,000? Or will i not have to because 21,000 from last years cash isa. Please let me know if you have an answer. I just want to be prepared for having to declare anything later on. Thank you