Short answer: yes. But it's more nuanced than a regular mortgage. Let me walk you through it. What gives a trustee the authority to borrow? The trust document itself. Most well-drafted trusts in California give the trustee the power to encumber trust property — meaning they can take out a loan against it. Before doing anything — read the trust document. Look for language about borrowing, encumbering, or mortgaging property. If it's there — you have the authority to proceed. I