The five petition periods
Notice of deficiency. IRC 6213(a) allows a petition “Within 90 days, or 150 days if the notice is addressed to a person outside the United States, after the notice of deficiency authorized in section 6212 is mailed (not counting Saturday, Sunday, or a legal holiday in the District of Columbia as the last day).” The period runs from mailing, not receipt. That is normally the date printed on the notice, but IRM 4.8.9.24.2 cautions that “The date on the letter is not determinative because it could be wrong”: the date the IRS deposited the letter in the mail, shown by the postmark or the certified mail list, controls, so use the envelope when you have it. The notice also prints the last day to file, and “Any petition filed with the Tax Court on or before the last date specified for filing such petition by the Secretary in the notice of deficiency shall be treated as timely filed,” so the calculator reports the later of the computed and printed dates. IRM 4.8.9.9.2.9 notes that a notice to a military address routed overseas was held to be “mailed to an address outside the United States,” so the 150 days applied. See the notice of deficiency guide, CP3219A and Letter 3219.
CDP determination. IRC 6330(d)(1): the person “may, within 30 days of a determination under this section, petition the Tax Court for review of such determination.” Lien determinations follow the same rule through IRC 6320(c). The CDP deadline calculator covers the hearing request that precedes the determination.
Innocent spouse. IRC 6015(e)(1)(A) allows a petition after the earlier of the mailing of the final determination by certified or registered mail or six months after the request, and “not later than the close of the 90th day after” the final determination is mailed; Treas. Reg. 1.6015-7(b) restates the 90 days. See innocent spouse relief and Form 8857.
Whistleblower. IRC 7623(b)(4): an award determination “may, within 30 days of such determination, be appealed to the Tax Court.”
Passport certification. IRC 7345(e)(1) allows an action in a district court or the Tax Court after the Commissioner notifies the individual and sets no filing period; Rule 351 states none either. The calculator reports that no statutory deadline exists. See passport certification.
Counting the days
Tax Court Rule 25(a)(1) states the method: “exclude the day of the event that triggers the period,” “count every day, including intermediate Saturdays, Sundays, and legal holidays,” and “include the last day of the period, but if the last day is a Saturday, Sunday, or legal holiday, the period continues to run until the end of the next day that is not a Saturday, Sunday, or legal holiday.” IRC 7503 says the same for every act under the internal revenue laws, and Treas. Reg. 301.7503-1(a) lists “the filing of a petition with the Tax Court for redetermination of a deficiency” among them. The holidays are the District of Columbia legal holidays; Rule 25(a)(5) names the federal holidays, any day declared a holiday by the President or Congress, and “any other day that the District of Columbia has declared a holiday, including District of Columbia Emancipation Day” (April 16). The calculator uses the list in IRM 25.6.1.6.18 with the federal observance rules (a Saturday holiday observed on Friday, a Sunday holiday on Monday) and Inauguration Day every fourth year.
Filing: DAWSON, mail and the clock
Rule 22(d): “A paper will be considered timely filed if it is electronically filed at or before 11:59 p.m., eastern time, on the last day of the applicable period for filing,” and the Court’s DAWSON page repeats that a document “is timely if it is electronically filed by 11:59 p.m., Eastern time, on the day it is due.” Paper must otherwise be “filed with the Clerk in Washington, D.C., during business hours” (Rule 22(a)). Rule 22(c) incorporates IRC 7502 for mail: a petition delivered late is treated as filed on the postmark date if it was “deposited in the mail in the United States in an envelope or other appropriate wrapper, postage prepaid, properly addressed,” and IRC 7502(f) extends the rule to designated private delivery services. Two tolling rules sit outside the arithmetic: IRC 7451(b) tolls the period when “a filing location is inaccessible or otherwise unavailable to the general public on the date a petition is due” for the days of inaccessibility plus 14, and bankruptcy suspends the deficiency period while the debtor is barred from filing “and for 60 days thereafter” (IRC 6213(f)(1)), the CDP period for the bar plus 30 days (IRC 6330(d)(2)). Rule 25(c)(2)(C) is the other side: the statutory period “cannot be extended by the Court.”
Late petitions
For CDP determinations the Supreme Court held in Boechler, P.C. v. Commissioner, 596 U.S. 199 (2022), that the 30-day limit in IRC 6330(d)(1) “is an ordinary, nonjurisdictional deadline subject to equitable tolling,” while leaving whether tolling is warranted to the facts of each case. For deficiency notices, IRM 4.8.9.12.3 states the IRS position that “The Tax Court does not have jurisdiction over a case when the taxpayer files a petition after the 90th/150th day or, if later, the date shown on the notice as the last day to file the petition,” and the calculator reports a late deficiency petition as late without a tolling note. The remaining routes are refund suits and claims or audit reconsideration; the Tax Court petitions guide and small tax case procedure cover the petition itself.
Checked against published examples
Treas. Reg. 301.7503-1(a) works an example in which a period “expires on Thursday, November 23, 1995 (Thanksgiving Day),” so the act is timely on Friday, November 24, 1995; a 90-day period from August 25, 1995 ends that Thursday, and the calculator returns Friday, November 24, 1995. Treas. Reg. 301.6330-1(c)(3) runs 30 days from a June 24, 1999 notice to Saturday, July 24, moving to Monday, July 26, 1999; entered as a CDP determination, the calculator returns July 26, 1999. The Emancipation Day table in IRM 25.6.1.6.18 gives the April results: when April 15 is a Friday the next business day is Monday, April 18; when it is a Saturday, Tuesday, April 18; when it is a Sunday, Tuesday, April 17. The calculator reproduces all three with 90-day periods from January 15, 2022, 2023 and 2018.
Questions practitioners ask
Does the 90 days run from the date my client received the notice?
No. IRC 6213(a) counts from the date the notice is mailed, whether or when it was received. The mailing date is the date the IRS deposited the letter in the mail, normally the date on the notice; the postmark or certified mail list controls if they differ.
The notice shows a last day that is wrong. Which date counts?
The later one. IRC 6213(a) treats a petition filed by the date specified in the notice as timely, and the statutory period applies if the printed date is earlier. IRM 4.8.9.24.2 instructs IRS reviewers that a wrong printed date does not invalidate the notice.
Is a petition mailed on the last day timely?
Yes if it goes by U.S. mail, properly addressed with postage prepaid, and bears a timely postmark (IRC 7502; Rule 22(c)), or by a designated private delivery service with a timely recorded date (IRC 7502(f)). Registered or certified mail gives prima facie evidence of the date.
Can the Tax Court extend the deadline if we ask before it runs?
No. Rule 25(c)(2)(C) says the period fixed by statute for filing a petition cannot be extended by the Court. Only statutory suspensions (bankruptcy, inaccessibility under IRC 7451(b)) or, for CDP cases after Boechler, equitable tolling can move it.
What time of day does the period end?
For electronic filing through DAWSON, 11:59 p.m. Eastern time on the last day (Rules 22(d) and 25(a)(3)(A)). For paper filed with the Clerk, when the Clerk's Office closes (Rule 25(a)(3)(B)). For mail, a postmark dated the last day is enough.