You file a Form 8857 asking the IRS for innocent spouse relief. Then you wait. Months go by. Nothing shows up in your mailbox. So you eventually file a petition with the U.S. Tax Court to get someone to look at your case.
Then the IRS tells you that you are too late. It says it mailed you a final determination notice a while back, the 90-day clock ran out, and the court has no power to hear you. You never saw the letter. The IRS says that does not matter. What matters, it says, is that the notice was mailed.
So what does the IRS actually have to prove? Is a tracking number printed on the letter enough? Does the envelope matter? And who carries the burden when the IRS cannot find its own mailing records? And what happens if the IRS records show something different than the US Postal Service records?
The recent Wales v. Commissioner, T.C. Memo. 2026-82, case provides an opportunity to consider these questions.
Facts & Procedural History
The taxpayer had field a joint income tax return. The taxes were not paid, so there was a balance owed to the IRS.
The taxpayer mailed the IRS a Form 8857, Request for Innocent Spouse Relief, in 2023. The form was submitted to ask the IRS to relieve her of joint liability for the tax from the joint income tax return.
Then, as far as she was concerned, nothing happened. She says she never received a final determination notice back from the IRS. This is actually very common. The IRS gets a lot of mail and processes quite a bit of it. But many submissions never receive a response from the IRS.
In December 2025, more than two years after mailing the request, the taxpayer filed a petition with the U.S. Tax Court. Her petition said that the IRS had never issued her a final determination.
The IRS moved to dismiss the case for lack of jurisdiction. It said it had issued a final determination notice, that it mailed the notice by certified mail to her last known address, and that the 90-day window to petition had closed long ago.
The IRS produced the determination notice itself. It had a tracking number printed in the left-hand corner and the words “certified mail” on the first page. It produced the envelope. It produced a voucher stamped as received at an IRS campus support unit. And it produced the USPS tracking history for the number printed on the notice. The tracking history showed a delivery attempt in early 2025, a notice left at the address, a redelivery reminder, and the item eventually being returned to the IRS as unclaimed.
So the envelope was what mattered. The outside of the envelope said the item was sent by presorted first-class mail. It had no stamp, no sticker, and no marking of any kind indicating certified or registered mail.
The IRS also did not produce a Form 3877. We’ll come back to this.
Two Different Doors Into Tax Court
Section 6015 is the provision that lets one spouse ask to be relieved of joint liability for tax reported on, or resulting from, a joint return. This is not a new provision. It has been around in its current form since 1998. It has been a valuable tool for those who filed a joint return and later found themselves with a tax bill they did not create.
Getting relief from the IRS is one thing. Getting into court is another. The U.S. Tax Court is a court of limited jurisdiction. It only hears the types of cases that Congress says it can hear.
Section 6015(e)(1)(A) is the grant of jurisdiction, and it is written in a way that is easy to misread. It says a taxpayer may petition the court if the petition is filed “at any time after the earlier of” two dates. The first is the date the IRS mails, by certified or registered mail to the taxpayer’s last known address, notice of its final determination. The second is the date six months after the request for relief was filed. The statute then adds that the petition must be filed “not later than the close of the 90th day” after the first of those two dates.
Given the language, there are two doors in. The six-month date opens a door. The determination notice opens a door too, but it also starts a 90-day shot clock that shuts that door.
Looking at the rules, the 90-day deadline does not depend on the date the IRS mailed the notice. It depends on the date the IRS mailed the notice by certified or registered mail. That is the language in the statute. If the IRS cannot prove certified or registered mail, there is no starting date under that subclause. And if there is no starting date, there is no 90-day deadline to blow.
Who Has to Prove the Notice Was Mailed?
So who has to prove the notice was mailed? The IRS does.
When the IRS asks a court to throw a case out because a notice was mailed, the IRS has the burden of proving proper mailing with competent and persuasive evidence. The tax court has said in prior cases that this means showing the notice was actually delivered to the Postal Service for mailing.
This makes sense as a matter of fairness. The taxpayer is being asked to prove a negative–that a letter never arrived. Nobody can prove that. The IRS, on the other hand, controls its own mailing operation and generates its own records. So the IRS is the party that has to come forward with proof.
The same framework applies to a notice of deficiency, which is what most of this caselaw involves. The tax court borrowed that deficiency caselaw here and applied it to a Section 6015 determination notice. That is worth noting, because it means the mailing rules taxpayers have used for decades in deficiency cases now carry over into innocent spouse cases.
What Does the IRS Normally Use to Prove It?
So how does the IRS usually prove mailing? A Form 3877.
This is the U.S. Postal Service mailing book the IRS uses when it hands a stack of mail to the post office. The postal clerk receives the batch and the form comes back showing what went out, on what date, to whom.
A properly completed Form 3877 is direct documentary evidence of both the date and the fact of mailing. If the existence of the notice itself is not in dispute, a clean Form 3877 is enough on its own. Even a defective Form 3877 still counts for something. The IRS can combine it with other evidence to carry the burden.
Without any Form 3877, the IRS is not out of luck. It can still win by presenting what the court calls “otherwise sufficient” evidence. In prior cases, the court has accepted a certified mailing list that referenced the notice and its mailing date and was stamped and initialed by the postmaster. It has also accepted a computerized certified mailing list that provided the same information a Form 3877 would. There are cases that go the other way, but you get the picture. The IRS needs something that ties this notice, to this date, to this class of service.
Why Wasn’t the Tracking Number Enough?
So why wasn’t the tracking number enough.
The short answer is that a tracking number proves that something moved through the mail. It does not prove how it moved through the mail.
The IRS had three pieces of paper it thought closed the gap. It had the notice with “certified mail” printed on it. It had a USPS Tracking Plus statement showing the full tracking history. And it had a certification from a USPS paralegal specialist vouching for the accuracy of that tracking history.
None of the three said the one thing this particular statute required. The tracking number by itself does not identify the class of service. The Tracking Plus statement did not indicate whether the item was sent certified or registered. And the paralegal’s certification did not say it either. The IRS had a lot of documents, and not one of them answered the question.
Meanwhile the actual physical envelope that went through the mail affirmatively said presorted first-class. So the IRS was in the position of arguing that a letter was sent certified while showing the envelope that said it was not. The court found that it remained entirely unclear whether the notice was ever actually sent by certified or registered mail.
The IRS lost its motion. Because the IRS could not establish certified or registered mailing, there was no date under the first subclause and no 90-day deadline. The taxpayer had filed more than six months after her request, so the second door was open. The court held it had jurisdiction and denied the motion to dismiss.
What Does This Mean Outside of Innocent Spouse Cases?
This leads to the question of how far the reasoning goes. Does it apply to other types of cases?
The answer is that it does. The tax code specifies certified or registered mail in a number of places, and the same logic should apply anywhere Congress wrote those words into the statute rather than just saying “mail.” The class of service is not a formality in those provisions. It is an element the IRS has to prove.
There is also a practical point buried in this opinion that is easy to miss. The IRS’s own notice said “certified mail” on its face, and IRS agents apparently believed it had gone out that way. The envelope said otherwise. That kind of mismatch between what an IRS notice claims and what the mailing record shows is worth looking for. We have seen similar problems when the IRS sends mail to the wrong address, and the fix in both situations starts with getting the actual envelope and the actual mailing records rather than accepting the IRS’s description of them.
It is worth being clear about what the taxpayer won here. She won the right to have her case heard. She did not win innocent spouse relief. The merits are still ahead of her. But a jurisdictional dismissal is the end of the road, and she avoided it.
The Takeaway
Deadlines in tax cases usually run against the taxpayer, so it is easy to assume the IRS has the paperwork to back up a late-filing argument. It often does not. Where a statute says the IRS must mail a notice by certified or registered mail, the IRS has to prove that class of service, and a tracking number printed on the notice will not do it. If the IRS says you missed a 90-day window on a notice you never received, ask for the Form 3877 and ask for the envelope. If the envelope says first-class, the clock may have never started.
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