The tax you pay is your responsibility and will depend upon your individual circumstances. This may include capital gains or income tax and if you need advice on the impact of additional income or capital gains you should discuss this with a tax advisor prior to making an investment.
If you are making an Equity investment your investment is in an SPV. The taxable profit generated by the SPV is subject to corporation tax at 20% and rental income will be paid as Dividends, net of Corporation Tax and may be liable for Income tax. Please note that the corporation tax may be subject to change.
If you are making a Debt Investment, then you are lending to the SPV and gaining interest in return. The SPV may be required to withhold tax at the basic rate. If this is the case it is explained in the instrument document for each investment.