'We are still a long way off a simple Isa regime'

And for anyone who does not use the full £20,000 allowance, there is no reason to open a UK Isa instead of a standard stocks and shares Isa that offers all the same investment options, plus many, many more.

There is also a question of whether the UK Isa will be allowed to pay interest on cash, so it could well end up as a poor alternative.  

Time will tell if the UK Isa ever comes into existence, but even without it, we are still a long way off a simple Isa regime. 

Lisa Webster is a senior technical consultant at AJ Bell