We must first decide whether the statute of limitations bars the assessment of the deficiency in2005 Tax Ct. Summary LEXIS 101">*105 issue. In doing so, we must decide when petitioner filed his return.

Generally, an income tax must be assessed within 3 years after the applicable return is filed (whether or not such return was filed on or after the date prescribed). Sec. 6501(a). The bar of the statute of limitations on assessment is an affirmative defense, and the party raising it must specifically plead it and carry the burden of proving its applicability. Rules 39, 142(a). If the taxpayer makes a prima facie case proving the filing date of his or her income tax return and the expiration of the statutory period prior to the mailing of the notice of deficiency, the burden of going forward with the evidence shifts to respondent. Robinson v. Commissioner, 57 T.C. 735">57 T.C. 735, 57 T.C. 735">737 (1972). The burden of proof, i.e., the burden of ultimate persuasion, however, always remains with the party who pleads that the assessment is barred by the statute of limitations. Adler v. Commissioner, 85 T.C. 535">85 T.C. 535, 85 T.C. 535">540 (1985).

Petitioner contends that he filed his return on September 3, 1999, and that the period of limitations ordinarily would have expired on September 3, 2002. Petitioner testified at trial that, as2005 Tax Ct. Summary LEXIS 101">*106 a matter of personal habit, on the night he completes a return, he signs and dates it, he has his wife sign and date it, he makes a copy of it at the copy store, and then mails it at the local post office. With regard to his 1998 return, petitioner asserts that he and his wife signed it on September 3, 1999, that he made a copy of it, and that he mailed it at the local post office by regular mail on the same day. Petitioner further asserts that he learned that respondent did not receive his return only when respondent's Memphis Service Center contacted him in the spring of 2003, at which time petitioner mailed respondent a copy of his return. ⁵ In contrast, respondent's records show that respondent first received and filed petitioner's 1998 return on July 10, 2003.

Under certain circumstances, this Court may accept the credible testimony of witnesses regarding2005 Tax Ct. Summary LEXIS 101">*107 the preparation and mailing of a tax return when the Commissioner's records do not show receipt of a return and the taxpayer cannot provide any documentary evidence of the filing of such return. See Sorrentino v. IRS, 383 F.3d 1187">383 F.3d 1187, 383 F.3d 1187">1193-1194 (10th Cir. 2004); Estate of Wood v. Commissioner, 92 T.C. 793">92 T.C. 793, 92 T.C. 793">796-798 (1989) (testimony of postal employee who affixed postmark to return), affd. 909 F.2d 1155">909 F.2d 1155 (8th Cir. 1990); Mitchell Offset Plate Serv., Inc. v. Commissioner, 53 T.C. 235">53 T.C. 235, 53 T.C. 235">239-240 (1969) (testimony of corporation's shareholders and its accountants). However, a taxpayer's own testimony concerning his or her habit regarding the preparation and mailing of his or her returns is not sufficient by itself. See Longazel v. Commissioner, T.C. Memo. 1994-487; Duralia v. Commissioner, T.C. Memo. 1994-269.

Based on the entirety of the record, petitioner's testimony does not establish that he filed his return on September 3, 1999. Moreover, the fact that petitioner also did not file his individual Colorado State income tax return until July 2, 2003, suggests that he filed both his Federal and State income tax2005 Tax Ct. Summary LEXIS 101">*108 returns at about the same time. We thus conclude that petitioner failed to carry his burden of proving that he filed his return on September 3, 1999. Rather, based on the evidence adduced, we hold that petitioner filed his 1998 return on July 10, 2003. Accordingly, the statute of limitations does not bar the assessment of the deficiency at issue.

Pursuant to section 6651(a)(1), respondent determined that petitioner is liable for an addition to tax. Section 6651(a)(1) imposes an addition to tax for the failure to file a return within the period of time prescribed (determined with regard to any extension of time for filing), unless the taxpayer shows that such failure was due to reasonable cause and not due to willful neglect.

Section 7491(c) provides that the Commissioner will bear the burden of production with respect to the liability of any individual for additions to tax. "The Commissioner's burden of production under section 7491(c) is to produce evidence that it is appropriate to impose the relevant penalty, addition to tax, or additional amount". Swain v. Commissioner, 118 T.C. 358">118 T.C. 358, 118 T.C. 358">363 (2002); see also Higbee v. Commissioner, 116 T.C. 438">116 T.C. 438, 116 T.C. 438">446 (2001).2005 Tax Ct. Summary LEXIS 101">*109 The Commissioner, however, does not have the burden to introduce evidence regarding reasonable cause or substantial authority. 116 T.C. 438">Id. at 446-447. Section 7491(c) applies to examinations commenced after July 22, 1998.

Petitioner had an extension of time to file his return until August 15, 1999. Petitioner did not file a return by August 15, 1999. Indeed, petitioner testified at trial that he allegedly mailed his return to respondent on September 3, 1999, after the due date as extended. Accordingly, respondent met his burden of production for the section 6651(a)(1) addition to tax.

Petitioner did not present any persuasive evidence that his failure to timely file a return was due to reasonable cause and not due to willful neglect. See 116 T.C. 438">Higbee v. Commissioner, supra at 446-447. Accordingly, petitioner is liable for the section 6651(a)(1) addition to tax for 1998.

We have considered all of petitioner's arguments, and, to the extent that we have not specifically addressed them, we conclude that they are without merit.

Reviewed and adopted as the report of the Small Tax Case Division.

To reflect our disposition of the disputed issues, as well2005 Tax Ct. Summary LEXIS 101">*110 as the parties' concessions, ⁶

Decision will be entered under Rule 155.