TC 161: Abatement of Failure to File Penalty

What the code actually does

TC 161 is the credit transaction that abates a Failure to File penalty already assessed, in whole or in part. Doc 6209 §8A (the IRS’s own internal Master File Codes reference, a free public PDF on IRS.gov) titles it “Abatement of Delinquency Penalty” and states verbatim: “Abates previously posted 160, 166 Delinquency Penalty liability assessment in whole or in part. Penalty is not recomputed by computer.” That last sentence is the important one — TC 161 records a discretionary, human-entered figure, not the system correcting its own math. That is a genuinely different mechanism from TC 167, covered below.

Notice exactly what TC 161 reaches: “previously posted 160, 166” — both the manually computed assessment (TC 160) and the computer-generated one. One abatement code answers either kind of assessment. The reverse is not true: only TC 167 can close out a TC 166, and it cannot touch a TC 160 at all.

Three roads to the same code

A bare TC 161 on a transcript does not say why the penalty came off, and the real reason changes the conversation with the client considerably. Two of the three possible reasons are genuine relief determinations — First-Time Abate and reasonable cause, both discussed below. The third is not relief at all; it is a correction of a penalty that should never have posted. IRM 20.1.2.2.1 gives the concrete example: “If IRS assessed a late filing penalty in error on a timely filed return... abate the penalty with Transaction Code (TC) 161 and Penalty Reason Code (PRC) 027, timely mailed/timely filed.” A PRC 027 abatement means the return was never actually late — nothing about the client’s compliance history or the strength of a reasonable-cause narrative is at issue, because there was never a valid penalty to excuse in the first place.

Confirming which of the three actually happened belongs in the file. An FTA or reasonable-cause abatement uses up, or at least documents, relief the client may need again on a future year. A PRC 027 correction does not — it was never a real penalty, so it costs nothing on the compliance-history ledger.

Sequencing the relief request: First-Time Abate first

When the penalty genuinely is valid and a relief request is the actual path, sequence matters. IRM 20.1.1.3.3.2.1, First-Time Abate, reaches the “Failure to File (FTF) penalty under IRC 6651(a)(1), IRC 6698(a)(1), or IRC 6699(a)(1)” by name, and IRS.gov’s own summary states the compliance-history test in plain terms: the taxpayer qualifies if “the same return type, as the original return, was timely filed for the prior three years,” with no unabated penalty other than an estimated tax penalty in that lookback window. FTA needs no documentation of hardship or cause — it is the faster, cheaper request, and it should be checked first every time. That ordering hasn’t changed, but for original returns due in tax year 2025 and after, IRS.gov now describes a companion program, Automatic Exemption from Penalty (AEP), that applies the identical three-year compliance test automatically and can suppress the penalty before it is ever assessed. AEP has its own authority — IRM 20.1.1.3.3.2.5, Automatic Exemption from Penalty Administrative Relief, added by IRM Procedural Update sbse-20-0626-0643 on June 17, 2026, which states that AEP is administrative relief granted at original return processing and officially replaces First Time Abate for all eligible original returns due January 1, 2027 and after. Cite that procedural update by number rather than the published IRM: as of August 25, 2026 the consolidated IRM 20.1.1 on IRS.gov has not yet absorbed it — its 20.1.1.3.3.2 series still runs .1 through .4 with no .5 — so a practitioner who looks the subsection up today will not find it. So a posted Failure to File penalty on a current-year return is worth flagging as a possible AEP gap, not just a routine FTA request.

Reasonable cause is the fallback when the compliance history does not support FTA. IRM 20.1.1.3.2 sets the standard: relief “is generally granted when the taxpayer exercised ordinary business care and prudence in determining their tax obligations but was nevertheless unable to comply with those obligations.” That is a facts-and-circumstances showing, not a checklist, and it takes real documentation to support — worth reserving for the cases where FTA genuinely is not available.

The practitioner’s actual next step

Run the compliance-history check before drafting anything — The Federal Tax Desk’s Penalty Abatement Analyzer checks First-Time Abate and reasonable-cause eligibility together, accounts for the ongoing AEP transition, and sequences which one to request first, rather than guessing.

If FTA is off the table, build the reasonable-cause narrative around ordinary business care and prudence — what specifically prevented timely filing, and what the client did once the obstacle was known — rather than a general hardship story.

If the transcript shows a PRC 027-style correction rather than a relief grant, say so plainly to the client: the account is clean because the penalty was wrong, not because a relief benefit was spent. That distinction protects a future year that might actually need FTA.

What TC 161 gets confused with

TC 161 and TC 167 are the pair most worth separating cleanly, because both are credit transactions that reduce or remove the identical Failure to File penalty — and only one of them means a relief determination happened. TC 161 is manual and discretionary; per Doc 6209, the penalty it abates “is not recomputed by computer.” TC 167 is the opposite: a “Generated Transaction” that reverses only a TC 166, triggered by “change... in return due date or tax due at due date,” with no reasonable-cause or FTA analysis behind it at all. A TC 167 on the account does not mean the client received relief, and it does not mean a TC 161 request is unnecessary if the penalty (or part of it) is still standing.

TC 161 also gets confused with TC 162, since both can follow a TC 160 or TC 161 posting in short order. They are not the same kind of code: TC 161 moves a dollar amount off the account. TC 162 moves nothing — it only removes the restriction that a manual entry leaves behind, so the system can compute the penalty normally again going forward.