Social Investment Tax Relief (SITR) came in on 6th April 2014.
Individuals making an eligible investment at any time from 6 April 2014 can deduct 30% of the cost of their investment from their income tax liability for 2014/15 (or the relevant later year in which the investment is made). The minimum period of investment is 3 years.
The income tax and capital gain tax reliefs provide a substantial incentive for investors. To make sure new investment is directed to the organisations which need it most and to meet EU regulations, the investment and the organisation receiving it must meet certain criteria.
Organisations must have a defined and regulated social purpose. Charities, community interest companies or community benefit societies carrying out a qualifying trade, with fewer than 500 employees and gross assets of no more than £15 million may be eligible.
The tax relief is available on unsecured loans as well as shares.
So basically, if you are a basic rate tax payer using SITR will be better than Gift Aid.
Not only do you get the tax relief but if you give a loan it will be repaid (after 3 years).