CONSIDERING setting up a trust for yourself? While popular in many regions as vehicles for minimising tax, trusts are not as common among Hong Kong people because of the territory's relatively low taxes. The problem is, unless the investor has vast wealth, the costs of these trusts - which are not to be confused with unit trusts - may outweigh the rewards. Under a trust arrangement, the owner of assets transfers legal title to a trustee or trustees. A trustee can be an individual, but more often a trustee is a trust company associated with a bank or a professional firm of accountants or solicitors. Under the arrangement, the trustee becomes the legal owner of the assets while the individual - known as the settlor - and those nominated by the individual become the beneficial owners of the assets. Once a settlor has transferred ownership of his assets, he cannot be taxed on the income, or on any capital gains, which are no longer rightfully or legally his but are those of the trust. In terms of inheritance planning, a trust can be used by people who want their beneficiaries to enjoy financial security but do not want them to have full ownership of the assets until they reach a certain age or have assumed certain responsibilities. Italso means that if the settlor dies, his estate will not be held in probate. But while it may sound simple, setting up and running a trust can be costly. For this reason, those people of higher net worth tend to be more suitable settlors. The expense first kicks in when setting up a trust deed. This is done to exact specifications, which inevitably means consulting a professional. ''That initial cost is partly why small trusts may be uneconomic,'' said Kate Richardson, senior tax manager at Price Waterhouse. ''A professional firm may charge a minimum flat fee of say, $10,000 to set up a trust.'' Banks can also be used. They are more likely to base their charges on the percentage of the value of the assets to be transferred into the trust. Those who use banks to set up trusts are often high-net-worth individuals already using the bank for other private banking services. In addition, the appointment of professional trustees or a professional investment manager will mean incurring ongoing fees as well.