Fixed Rate ISA 2023/2024

I opened a fixed rate ISA in April 2023 and added money and a transfer from an existing ISA between April and May 2023 (two separate transactions, one in April and one in May 2023). I then became non UK resident in June 2023. My current fixed rate ISA provider has now informed me that according to 'HMRC rules require us to remove any subscriptions that have been made since the start of the tax year in which you became non-resident', thus they issued a cheque for what they believe to be the invalid subscription and paid interest. My understanding is that if I open an ISA in the UK and then move abroad, I cannot put money into it AFTER the tax year that I move, and that I can keep my ISA open and still get UK tax relief on money held in it. If I understand correctly then, for the tax year 2023/2024 the money is a valid ISA subscription, however I cannot put any money into it for the tax year 2024/2025. If this is the case I believe my ISA provider is incorrect. Or am I missing anything? Thank you in advance for any clarification.

Hi,
You are correct:
Individual Savings Accounts (ISAs)
Thank you.

Thank yuou @HMRC_Admin_8 My provider has now quoted Non-UK residence confirmed at https://www.gov.uk/guidance/who-can-invest-in-an-isa-if-youre-an-isa-manager#the-residence-qualification and made a reference that since 2013 they are obliged to do so; which seems a contradiction to what's stated on the Individual Savings Acounts (ISA) page. Any clarification please?

Hi,

You can pay into an ISA in the tax year that you leave the UK or arrive in the UK and have the benefit of the £20000 annual subscription limit, but not in tax years that you are not tax resident in the UK.  

You cannot make payments into any ISAs or create new ISA when you are not resident in the UK.

Thank you.