In the hope of simplifying the discussion (assuming launch of IFISA and current rules are unchanged and ISA manager terms permit)
All non ISA money is in Jar C
ISA money is split into 2 main Pots
Pot A - current financial year money (eg 2016/17
Pot B - previous year(s) money.
Rule 1 - Pot A can have between £0 & £15240 added to it from Jar C, and money can be added to Pot A from Jar C at any point during the year as long as the total doesnt exceeed this maximum.
Rule 2 - Pot A can be divided into a max of 3 parts:
Potlet A1 - cash ISA (includes help to buy ISA)
Potlet A2 - share ISA
Potlet A3 - independent finance ISA (ie P2P)
Rule 3 - Potlets A1-A3 can each contain any percentage of the total amount in Pot A but collectively no more than £15240. Money can be moved between Potlets A1, A2, A3 at any time.
There are many Boxes (ISA Managers)
Rule 4 - Each Potlet A1, A2, A3 can only ever be in one Box, they can be in the same Box, or 3 different Boxes. (There are no cats, dead or alive, in any box)
Rule 5 You can move any of Potlets A1, A2, A3 to a different Box but the whole Potlet has to move.
Pot B can be anything from £0 -£1mil+ if youd invested all eligible sums in previous years (including TESSAs)
Pot B can be subdivided into as many individual Potlets as you like and in as many Boxes as you like. Any of these individual Pots can be in the same Box as any of the Potlets A1, A2, A3 but dont have to be.
At the end of the financial year, everything in Pot A (including any interest/profits) is added to Pot B and a new Pot A is created.
Hopefully this doesnt drive eveyone to hide in a Box because theyve gone Potty and turned into Jar Jar Binks
