Lucas v. Earl, 281 U.S. 111 (1930), is a United States Supreme Court case concerning U.S. Federal income taxation, about a man who reported only half of his earnings for years 1920 and 1921. Earl C. Guy and his wife had entered into a contract that would potentially save a lot of tax. The contract specified that earnings were owned by the couple as joint tenants. It is unlikely that it was tax-motivated, since there was no income tax in 1901 when they executed the contract. Justice Oliver Wendell Holmes, Jr. delivered the Court’s opinion which generally stands for the proposition that income from services is taxed to the party who performed the services. The case is used to support the proposition that the substance of the transaction, rather than the form, is controlling for tax purposes.