n. the act of mixing the funds belonging to one party with those of another party, or, most importantly with funds held in trust for another. Spouses or business partners may commingle without a problem, except that a spouse may thus risk turning separate property into community property (transmutation), and a business partner may have to account to the other. However, trustees, guardians or lawyers holding client funds must be careful not to commingle those funds with their own, since commingling is generally prohibited as a conflict of interest. Use of commingled funds for an investment, even though it might benefit both the trustee and the beneficiary, is still improper. Inadvertent commingling or temporary commingling (say, upon receipt of a settlement check in which both the client and attorney have an interest) requires prompt separation of funds and accounting to the client or beneficiary. To avoid commingling, trustees, lawyers, guardians and those responsible for another's funds set up trust accounts for funds of another.