Section 415
The court may reform the terms of a trust, even if unambiguous, to conform the terms to the settlor's intention if it is proved by clear and convincing evidence that the settlor's intent or the terms of the trust were affected by a mistake of fact or law, whether in expression or inducement.
Procedural advisory commentary (2013)
Section 415 empowers the court to reform the terms of a trust, even if those terms are unambiguous, in order to conform the trust to the settlor’s intention if it is proved by clear and convincing evidence that the settlor’s intent or the terms of the trust were affected by a mistake of fact or law, whether in expression or inducement. This provision is consistent with present Massachusetts practice with respect to inter vivos trusts, and clarifies that the same principles apply to testamentary trusts.