Has anyone paid off an ISA mortgage early ?? How did you go about it ??

[RubbingHimSourly]

Obviously it's different to just going in and paying it off as the ISA is seperate to the building society. But who do I need to contact ??

I've had a small windfall which will just about cover the balance. We then intend on paying what we were paying into our mortgage into savings which will more than double our money.......if I can get the ball rolling 🧐