The below is from Moneyvator.com
PIDs within a tax shelter( eg an ISA)
You do not pay tax on PIDs held within tax sheltered accounts.
However, unlike ordinary dividends that are paid gross (i.e. with no tax deducted), PIDs are generally paid with 20% tax deducted.
This means the tax already paid needs to be clawed back .
Your tax-sheltered account should be issued with a 20% tax credit associated with your PID income, which the company that runs your ISA, CTF or pension should use to reclaim the tax paid from the taxman.
From the chat with Shanice of Freetrade, she told me that Freetrade do not support REITs in an ISA right now, as they require a 20% tax payment which we can’t operationally support at the moment, but if it is taken at source, then this has already been dealt with?