Just how much cash will you be able to hold in your ISA from next year and what will it cost you to do so? At first sight, new rules for individual savings accounts (ISAs) due to come into force from 6 April 2027 look straightforward. In practice, they are likely to prove anything but, thanks to tricky new regulations published this week.The confusion stems from changes announced in last November's Budget. Chancellor Rachel Reeves stressed her determination to use the tax system to encourage ris