Custodial Accounts (UGMA/UTMA)
Accounts an adult custodian manages for a minor under the Uniform Gifts/Transfers to Minors Acts: one custodian, one minor, gifts are irrevocable, the minor's Social Security number is used, and assets transfer at the age of majority.
The custodian invests prudently for the minor and may be reimbursed reasonable expenses but cannot borrow from the account. Income is taxed to the minor (kiddie-tax rules apply) — another way these differ from 529 plans.