Example. A is employed by B during the month of January 1955 in employment and is entitled to receive remuneration of $100 for the services performed for B, the employer, during the month. A leaves the employ of B at the close of business on January 31, 1955. On February 15, 1955 (when A is no longer an employee of B), B pays A the remuneration of $100 which was earned for the services performed in January. The $100 is wages and the taxes are payable with respect thereto.
26 C.F.R. §31.3121(a)-1