Filing a timely refund claim gets you in the door. If the IRS says no, or says nothing, the next step is a lawsuit, and that has its own clock. Section 6532(a) of the Internal Revenue Code sets both a waiting period and a deadline for refund suits, and it contains traps that catch people who are still trying to work things out with the IRS.

This guide covers when you can sue, when you must sue and the forms and IRS actions that start or fail to stop the clock.

The claim comes first

A refund suit requires a timely administrative claim. Treasury Regulation 301.6402-2(a)(1) says that under section 7422, a civil action for refund may not be instituted unless a claim has been filed within the applicable period of limitation. And section 301.6402-2(b)(1) says no refund will be allowed after the limitation period except on grounds set forth in a claim filed before the period expires.

In other words, the claim defines the lawsuit. Grounds that were not in a timely claim generally cannot be added later. The guide to the refund claim deadline covers the claim itself.

The waiting period

Section 6532(a)(1) says no suit for refund under section 7422(a) shall be begun before the expiration of 6 months from the date of filing the claim, unless the IRS renders a decision on it within that time.

So you generally wait six months or until the IRS decides, whichever comes first. If the IRS has not acted within six months, you may sue without waiting for a decision. Section 6532(a)(5) cross-references a 120-day period that replaces the six months in a bankruptcy case.

The deadline

The same paragraph sets the outer limit: no suit shall be begun after the expiration of 2 years from the date of mailing by certified mail or registered mail by the IRS to the taxpayer of a notice of the disallowance of the part of the claim to which the suit relates.

Three details matter. The clock runs from mailing, not receipt. The notice must go by certified or registered mail. And the clock runs separately for each part of a claim disallowed.

IRM 25.6.1 adds that to start the period, a notice of claim disallowance must unequivocally state that the claim was disallowed, must be mailed by certified or registered mail and must notify the taxpayer of the disallowance of the part of the claim to which the suit relates. It identifies Letter 105C, Claim Disallowed, and Letter 106C, Claim Partially Disallowed, as the notices, and says a math error notice is not a final notice of claim disallowance.

If the IRS never sends a notice

If the IRS never mails a qualifying notice of disallowance, the two-year period does not start. IRM 25.6.1 says the two-year period for filing a refund suit does not begin until the IRS sends a notice of claim disallowance, unless the taxpayer files a Form 2297 waiver. It adds that a claim requesting a refund of $1 or more holds an open statute on that issue until the claim is paid or disallowed by a proper notice or waiver.

That is good for the taxpayer. A claim the IRS ignores can be litigated after six months, and the outside deadline does not start running until a proper notice goes out.

Form 2297 starts the clock immediately

Section 6532(a)(3) says that if a person files a written waiver of the requirement to be mailed a notice of disallowance, the two-year period begins on the date the waiver is filed.

The IRS form is Form 2297, Waiver of Statutory Notification of Claim Disallowance. IRM 4.10.11 explains that signing it waives the requirement for a certified notice of claim disallowance and starts the two-year period on the date the waiver is filed. It also notes that Form 2297 does not count as a decision of the IRS for purposes of the six-month waiting period, so it does not let you sue sooner. Only an actual decision does that.

IRM 4.10.11 tells examiners to solicit Form 870, Form 4549 or Form 3363 in addition to Form 2297 when a claim is disallowed in an examination, so you may see them together. Read Form 2297 for what it is: a document that starts your litigation deadline. If you sign it, calendar two years from the date it is filed.

Reconsideration does not stop the clock

This is the trap. Section 6532(a)(4) says any consideration, reconsideration or action by the IRS with respect to the claim after the mailing of a notice of disallowance by certified or registered mail shall not operate to extend the period within which suit may be begun.

IRM 25.6.1 says the same: the IRS may reconsider a claim after issuing a final notice of disallowance, but reconsideration does not extend the period for filing a refund suit under IRC 6532(a).

People lose refund suits this way. They receive a disallowance, ask for reconsideration or go to Appeals, spend a year or more in discussions and then learn the two years ran while they talked. If you pursue reconsideration, track the two-year date anyway.

Extending the deadline by agreement

There is a proper way to get more time. Section 6532(a)(2) says the two-year period shall be extended for such period as may be agreed upon in writing between the taxpayer and the IRS.

If settlement discussions or reconsideration will take longer than the time left, ask for a written agreement extending the suit period before it expires. Do not rely on informal assurances. The statute requires a writing.

Where the suit is filed

A refund suit is a suit against the United States. It is different from a Tax Court petition, which challenges a proposed deficiency before payment. The refund route generally comes after the tax has been paid and a claim has been denied or ignored. The choice between paying and suing for a refund and petitioning the Tax Court before paying is a strategic decision with its own deadlines, and it often has to be made at the notice of deficiency stage, long before a refund suit is on the table.

Because a refund suit is filed in a court other than the Tax Court, section 7502(d)(1) means the postmark rule does not protect a complaint mailed near the deadline. Filing early, and filing in the manner the court requires, is the only safe practice.

Practical checklist

  • Confirm your claim was timely and stated every ground you intend to litigate.
  • Note the date the claim was filed. Six months from then is the earliest you can sue without an IRS decision.
  • When a Letter 105C or 106C arrives, note the mailing date and calendar two years from it, for each part disallowed.
  • If you sign Form 2297, calendar two years from the date it is filed.
  • If you seek reconsideration, keep the two-year date on the calendar. If you need more time, get a written extension under IRC 6532(a)(2).
  • Watch the mailing rules. The timely mailing rule under IRC 7502 does not apply to documents filed in any court other than the Tax Court, under section 7502(d)(1).

The bottom line

A refund suit cannot begin until six months after the claim, unless the IRS decides sooner, and must begin within two years after the IRS mails a certified or registered notice of disallowance under IRC 6532(a). Form 2297 starts the two years on the date it is filed. Reconsideration does not stop the clock; only a written agreement extends it. The claim you filed defines the case you can bring.