Seeking clarification on one aspect of the ISA reform 2024

I am seeking some clarification on the “Individual Savings Account (ISA) reform 2024”, as documented in Section 1 of HMRC’s tax-free savings newsletter 11 at: https://www.gov.uk/government/publications/tax-free-savings-newsletter-11/tax-free-savings-newsletter-11 Specifically, I refer to Section 1.2, which is entitled “Allow subscriptions to multiple ISAs of the same type, except for Lifetime ISA and Junior ISA”. I quote verbatim the first sentence in this section: “This change is not mandatory, and managers can choose to limit subscriptions to only one ISA held with them in any tax year.”. Of particular interest is the phrase “held with them” because it then appears that the sentence is referring only to the situation in which an investor is holding multiple ISAs with a single ISA manager, and that ISA manager can choose to limit subscriptions to one of the ISAs or allow subscriptions to more than one of the ISAs. But what happens if an investor holds ISAs with two different ISA managers? The sentence doesn’t appear to cover that situation. Specifically, if the investor subscribes to an ISA held with one ISA manager, can that ISA manager prevent the investor from subscribing to an ISA held with the other ISA manager in the same tax year? The remainder of Section 1.2 doesn’t cover this situation explicitly either. But, later in the section, it does state (quoted verbatim): “You are still responsible for making sure the overall ISA limit is not exceeded for subscriptions made with you. It’s not possible for you to know if investors are subscribing, or have subscribed, with other ISA managers, nor the amount of any such subscriptions. Individual investors remain responsible for managing their overall subscription limits.” (The occurrence of “you” here is referring to the ISA manager reading the newsletter.) So, this appears to be stating that, if an ISA manager wishes to prevent an investor subscribing to an ISA held with them and also subscribing to an ISA held with another ISA manager within the same tax year, the former ISA manager has no way of knowing about it and enforcing it. Correct? The reason I am seeking clarification is that I am currently in a discussion with a UK savings bank on this issue. They claim that they have a policy of not allowing multiple subscriptions, either to their own ISAs or to those of other ISA managers. But, since 6 April 2024, I can’t see how they can prevent me from subscribing to an ISA held with another ISA manager as well as to one of their ISAs.

Hi 

Previously, you were limited to opening only 1 ISA of a particular type in each tax year, such as a cash ISA.  
The ISA reform allows for the creation of more than 1 ISA of the same type in the same tax year.  An ISA provider can choose to limit you to creating one ISA with them in a tax year.  
This does not prevent you from creating an ISA of the same type, with other providers.  
Regardless of however many ISA's you create, you are still limited to a combined maximum saving of £20000.

Thank you