Sec. 41.6109-1 Identifying numbers.
Every person required under section 41.6011(a)-1 to make a return must provide the identifying number required by the instructions to the form on which the return is made.
[T.D. 6606, 27 FR 8518, Aug. 25, 1962, as amended by T.D. 7012, 34 FR 7695, May 15, 1969. Revised by T.D. 8879, 65 FR 17149-17164, Mar. 31, 2000.]