Section 6(1) of the Trust property Control Act, Act 57 of 1998 state:
Any person whose appointment as trustee in terms of a trust instrument ... shall act in that capacity only if authorized thereto in writing by the Master.
Therefore, unless you have been properly appointed and authorized by the Master of the High Court, do not act as a trustee and especially, do not enter into any written contract, as those contracts are unenforceable and cannot be ratified once the Masters authorization is subsequently received. This is because there can be no ratification of an agreement which a statutory prohibition has rendered ab initio void in the sense that it is to be regarded as never having been concluded.