The Lemon Fool

So how do flexible ISAs work?

If I withdraw, say £5k, a flexible ISA allows you to pay that back in without impacting on your ISA allowance. But if I then want to pay in £20k, using my full allowance, is that OK?

I ask because I changed providers last tax year, from a flexible ISA (where I withdrew some and then paid it back in) to a non-flexible ISA (where I subscribed my £20k allowance)

The new provider has now written to my to say I have exceeded my ISA subscription allowance last two year.

Here is a clear statement of the rules:

https://www.nationwide.co.uk/savings/he ... explained/

I expect that what you have done is OK. I suggest that you write back to your current inflexible provider to say what you have done, and why you believe that you have not over-subscribed.