Real estate investment trusts are known in the UK, as Property Income Distributions (PIDs). They are a vehicle that allows an investor to obtain broadly similar returns from their investment, as they would have, had they invested directly in property (IFM21005).
In the hands of the shareholder, Property Income Distributions (PIDs) are taxable as profits of a UK property rental business. The PID is received net of withholding tax, unless it is to a recipient entitled to gross payment (IFM28125)
IFM28125 - Real Estate Investment Trust : Distributions: administration: gross payment: SI2006/2867/Reg 7
On the SA108 and online return, the REITs, should be declared in the section 'income from land and property abroad'.