ISA Over-subscribed

Hi, My wife's cash ISA account over-subscribed for £100 for 23/24 tax year, I have already informed the service provider and they reversed that transaction. However, the service provider asked us to contact HMRC regarding this case, but we are unable to contact HMRC via phone (either hotline too busy, or the agent said nothing she can do about the ISA), could you please advise anything we should do?

Hi,

You would need to contact our Self Assesment team or write to us, including the National Insurance number on your letter:

H.M. Revenue and Customs,
Pay As You Earn,
BX9 1AS

Self Assessment: general enquiries

Thank you.