A trustee may not receive remuneration except:
1. By order of the court, if the trust is very onerous or the services of the trustee very valuable;
2. Under authority in the trust instrument;
3. By consent of all the beneficiaries, being all sui juris and absolutely entitled;
4. In the case of the Public Trustee, whose fees are fixed by the Treasury; moreover, where the court appoints a corporation to be a trustee, the corporation may charge such remuneration as the court authorises;
5. In the case of an advocate-trustee who may charge his costs unless acting alone; moreover the partner of an advocate-trustee may be employed by him on trust work and be paid his charges, so long as the partner alone is entitled to any profit;
6. If the trust property is situated abroad and the foreign law permits payment.