What "Tax Year" should I use to transfer a dividend?

Gilb

So I have 2 Stocks and shares ISAs,

• A - I opened a previous year and contributed nothing to in this tax year, holds things that cannot be held in B.
• B - has better rates than A but fewer choices.

If I want to transfer a dividend that got paid into A this tax year into B.
is it a

• Previous year because the dividend is only there due to previous year contributions and I have used none of my current ISA allowance to pay into A
• This year since the dividend was paid in this year.

I don't quite understand the purpose of the "Current Year" "Previous Year" distinction.

masonic

If you have contributed nothing to A this tax year, then A consists wholly of previous year subscriptions. Income and gains are treated as part of the tax year account that generated them. 

If you had both current and previous year contributions in A, then you could choose either, as the contents of an ISA is treated as being fungible.