One sign of sufficient wealth is the desire or need to establish a personal trust.

There are 10 million Millionaires in the United States. There are more billionaires now than ever before. A trust, which allows the owner to state specifically how funds will be used and can protect those funds from tax liabilities, has long been thought of as an adequate way to handle great wealth.

But trust ownership in the United States is surprisingly low, with only 30 percent of affluent households owning a personal trust. Only 10 percent of affluent households have those funds handled by a corporate or institutional trustee; a majority choose instead to self-trustee, a far more personal approach to handling the trust.

We wanted to know why those investors who use a corporate trustee made that choice. So we asked.

Our new report, Choosing a Trustee, offers answers to the question: Why are you using a corporate trustee to handle your personal trust? We spoke to investors who have a trust with a corporate trustee and asked them to explain their decision. The answers were varied and heartfelt.

Trust ownership is definitely more likely among the wealthier investors. Our wealth segmentation report Asset Allocation, Portfolios and Primary Providers explains that among Ultra High Net Worth investors with a net worth between $5 million and $25 million, 49 percent have assets in a trust structure. But only 7 percent of those use an institutional trustee to handle those funds.

Among Millionaires investors with a net worth between $1 million and $5 million, only 25 percent own a personal trust. Among investors with a net worth under $1 million, the percentage drops considerably.

The decision to set up a trust is followed by the decision as to who will handle the trust. Corporate trustees are preferred because of their expertise in managing accounts, understanding investment options, dealing with tax and other trust laws, and appropriate record-keeping. They also have none of the emotional ties that can sometimes complicate individual trust setups.

Also, managing a trust is time-consuming, and can be extremely complicated at times depending on family situations. Sometimes, it is just simpler to let a corporate trustee handle the account.

For Choosing a Trustee, we spoke to 50 high net worth investors, half of which used a corporate trustee. The qualitative report is highlighted by the remarks provided by the investors explaining their decisions, as well as their opinions on how the process of choosing a trustee can be improved and made easier.

”I wanted to be at arm’s length to the investments,’’ said one investor. “I wanted to distance myself from the daily exercise of trying to stay above water. On those occasions when I have gotten involved, more times than not, it has not worked out well.”

Expertise and the awareness of current laws, standards and investment opportunities make a corporate trustee the choice for investors who are looking for an expert.

“The issue for me was to find people who I felt had a level of skill that was superior to mine,’’ said another investor using a corporate trustee. “I was hoping I would be able to find people who are clever enough to be able to protect me.”