IRS Separation of Liability Relief: How Divorced and Separated Spouses Can Split a Joint Tax Debt

The Problem With Joint Returns When a Marriage Ends

When married couples file a joint federal tax return, they each accept full legal responsibility for the entire tax shown on that return — including any additional taxes, penalties, and interest that the IRS later determines are owed. This is called joint and several liability, and it means the IRS can collect the full amount from either spouse, regardless of who earned the income, who made the financial decisions, or what a divorce decree says about responsibility for taxes.

Joint and several liability is designed to protect the federal government's ability to collect what it is owed. But it creates a serious problem for people who are no longer married to the person who incurred the tax debt. A spouse who dutifully filed jointly, trusted their partner to handle finances, and later divorced may find themselves facing IRS collection action for a debt they had no meaningful role in creating. The IRS doesn't care that the marriage ended. The joint return created the joint obligation, and both signatories remain on the hook unless a specific legal remedy intervenes.

Congress addressed this problem through IRC Section 6015, which provides three distinct relief mechanisms for spouses seeking to limit their responsibility for joint tax liabilities. The most targeted of the three — and the most commonly misunderstood — is Separation of Liability Relief under IRC Section 6015(c). This article explains how it works, who qualifies, and when it provides better protection than the other forms of spouse relief.

The Three Forms of Spouse Relief: Where Separation of Liability Fits

Before examining Section 6015(c) specifically, it helps to understand how the three spouse relief options differ from each other:

Innocent Spouse Relief (IRC Section 6015(b)): Eliminates a requesting spouse's liability entirely for an understatement of tax on a joint return, but only if the requesting spouse had no knowledge and no reason to know of the understatement at the time the return was signed. This is an all-or-nothing determination — the requesting spouse either qualifies for full relief or gets none.
Separation of Liability Relief (IRC Section 6015(c)): Allocates the understatement of tax between the two spouses based on the items that gave rise to the deficiency. The requesting spouse becomes liable only for the portion of the deficiency attributable to their own income, deductions, and credits — not for the portion attributable to the other spouse's items. Importantly, Section 6015(c) does not require that the requesting spouse lacked knowledge of the understatement; instead, it applies a different and more specific standard discussed below.
Equitable Relief (IRC Section 6015(f)): A catch-all provision available when neither 6015(b) nor 6015(c) applies. The IRS evaluates all relevant facts and circumstances to determine whether it would be inequitable to hold the requesting spouse liable. Equitable relief is the only form of spouse relief available for underpayment of tax (as opposed to an understatement), and it is available regardless of current marital status.

Separation of Liability Relief under 6015(c) is the right tool to reach for when a divorced, legally separated, or long-separated spouse wants to limit their IRS exposure to their own portion of a deficiency — and can document which items on the joint return belonged to which spouse.

Who Qualifies for Separation of Liability Relief

Section 6015(c) is specifically for spouses who are no longer in the marriage that gave rise to the joint return. To be eligible to request Separation of Liability Relief, the requesting spouse must meet one of the following status requirements at the time the election is made:

Divorced or legally separated from the spouse with whom they filed the joint return;
Widowed; or
Not a member of the same household as the other spouse (or former spouse) at any time during the 12-month period ending on the date the election is filed.

The third category — not sharing a household for the prior 12 months — is important because it extends 6015(c) eligibility to couples who are informally separated but whose divorce has not been finalized. A spouse who moved out of the marital home more than a year ago may be eligible for Separation of Liability Relief even if no divorce decree has been entered yet.

There is no requirement that the requesting spouse lacked knowledge of the items giving rise to the deficiency at the time the return was signed. This is the key structural difference from Innocent Spouse Relief under 6015(b): a spouse who knew about the income or deductions that caused the understatement can still request Separation of Liability Relief. Knowledge of the understatement, however, becomes relevant in a specific and significant way discussed below.

How the Allocation Works: Splitting the Deficiency

When Separation of Liability Relief is granted, the IRS allocates the deficiency — the additional tax owed beyond what was reported on the original return — between the two spouses in proportion to each spouse's contribution to the items that gave rise to the deficiency. The allocation is based on what each spouse's tax liability would have been if they had filed a separate return for that year.

In practical terms, this means:

If the deficiency arose because the other spouse failed to report self-employment income from their business, that portion of the deficiency is allocated to the other spouse.
If the deficiency arose from an inflated deduction that both spouses claimed related to a property they jointly owned, the deduction — and the resulting tax — is allocated proportionally.
If both spouses had separate sources of income and one spouse underreported their income, the deficiency attributable to that underreported income is allocated to the spouse who earned it.

The requesting spouse bears the initial burden of producing evidence to establish the proper allocation. Once the requesting spouse introduces reasonable evidence, the burden shifts to the IRS to produce evidence to rebut the proposed allocation. Documentation matters: bank records, W-2s, 1099s, business records, Schedule C filings, and correspondence with tax preparers can all be relevant to establishing which items belonged to which spouse.

The Knowledge Bar: When Separation of Liability Relief Is Denied

Congress built a significant limitation into Section 6015(c): if the requesting spouse had actual knowledge of the item giving rise to the deficiency at the time they signed the return, the IRS will not allocate that item away from the requesting spouse. The requesting spouse remains fully liable for any portion of the deficiency tied to items they actually knew about when they signed.

This is a narrower standard than the "knew or should have known" test used in Innocent Spouse Relief under 6015(b). Under 6015(c), the IRS must establish actual knowledge — not constructive knowledge, not reasonable inquiry that would have revealed the item, and not general awareness that the other spouse had unreported income somewhere. The requesting spouse's actual knowledge of the specific item (the unreported income, the inflated deduction, the fraudulent credit) is what triggers the limitation.

The IRS has the burden of proving actual knowledge once the requesting spouse has made a prima facie case for separation of liability. Common IRS arguments that a requesting spouse had actual knowledge include:

The requesting spouse signed tax returns that included the item in prior years and had the same return structure;
The requesting spouse was involved in the business or activity that generated the unreported income;
Bank records show the requesting spouse received deposits from the unreported income source;
The requesting spouse signed contracts, loan applications, or financial statements that disclosed the item;
Testimony from the other spouse or from tax professionals who prepared the return.

Rebutting the IRS's actual knowledge argument is one of the most litigation-intensive aspects of Separation of Liability cases. Cases turn on specific facts — what the requesting spouse actually knew, what they had access to, and what their involvement in household finances looked like. This is not a process to navigate without professional representation.

Fraudulent Transfer Bar: Additional Limitation on 6015(c)

Section 6015(c) contains a second limitation that applies regardless of the requesting spouse's knowledge: if the requesting spouse and the other spouse transferred assets between themselves with the intent to defraud the IRS, Separation of Liability Relief is not available for the portion of the deficiency related to those assets. The IRS is entitled to look through asset transfers made to put property out of the government's reach when applying this limitation.

This provision is less commonly invoked than the actual knowledge bar, but it matters in cases involving divorce settlements where one spouse received significant assets in exchange for assuming tax liability, or where property was transferred shortly before or after the IRS began examining the joint return.

Comparing Separation of Liability to Innocent Spouse Relief: Which to Request?

In many situations, a spouse seeking relief will file an election under both 6015(b) and 6015(c) on the same Form 8857, allowing the IRS to consider both. This is the standard approach because the two forms of relief analyze different questions and may produce different outcomes:

6015(b) — Innocent Spouse: Best when the requesting spouse had no knowledge or reason to know of the understatement. If granted, it eliminates liability entirely for the relevant items. If the requesting spouse had some knowledge, they will not qualify under 6015(b).
6015(c) — Separation of Liability: Best when the requesting spouse was aware of some items but not others, or when the goal is to limit liability to one's own share rather than eliminate it entirely. Even with partial knowledge, 6015(c) can protect the requesting spouse from the other spouse's portion of the deficiency.
6015(f) — Equitable Relief: The fallback when neither 6015(b) nor 6015(c) applies. The IRS considers a list of factors including marital status, economic hardship, abuse, mental or physical health, and the requesting spouse's compliance history. Equitable relief is also the only available form of relief for joint return underpayments (where the tax was correctly reported but not fully paid).

The IRS automatically considers all three forms of relief when a requesting spouse submits Form 8857, even if the form only explicitly requests one type. However, presenting a clear argument for each applicable provision — with supporting documentation — produces better outcomes than leaving the analysis entirely to the IRS.

The Filing Process: Form 8857 and Timing Requirements

Separation of Liability Relief is requested on IRS Form 8857 (Request for Innocent Spouse Relief). Despite the form title, Form 8857 covers all three forms of spouse relief under Section 6015. The form asks for information about the marriage, the tax years at issue, the requesting spouse's knowledge of the items that caused the deficiency, the requesting spouse's financial situation, and the history of the marriage including any history of abuse or control.

Key timing rules apply:

A Section 6015(c) election must generally be made no later than two years after the date the IRS first began collection activity against the requesting spouse with respect to the joint liability. The two-year period runs from the first collection contact — not from the date of the audit or the date the deficiency was assessed.
Collection activity that starts the two-year clock includes a notice of intent to levy, a lien filing, or any other IRS collection action directed at the requesting spouse specifically.
The requesting spouse should not wait for collection action to begin before filing Form 8857. Proactively filing when a deficiency is proposed — before collection begins — is far preferable to waiting until an enforcement action triggers the deadline. Once the two-year window closes, 6015(c) relief is no longer available.

The IRS must notify the other spouse (or former spouse) when a Form 8857 is received, and the other spouse has the right to participate in the determination process. This notification requirement means the other spouse will learn that the requesting spouse is seeking to shift liability, which can create tension in situations where a divorce is not yet final or where the parties have ongoing disputes about tax obligations.

What Happens After You File Form 8857

After receiving Form 8857, the IRS assigns the case to a Taxpayer Advocate or specialist who reviews the documentation, contacts the nonrequesting spouse, and gathers information to evaluate the claim. The process typically takes six months to a year or more depending on the complexity of the case and the IRS's current inventory. During the pendency of a 6015 claim, the IRS is generally required to suspend collection activity against the requesting spouse for the amount at issue.

If the IRS denies the claim, the requesting spouse can petition the U.S. Tax Court for a de novo review of the denial. The Tax Court reviews Separation of Liability cases on the full record, not just the administrative record, which means additional evidence can be introduced at the Tax Court level. Many 6015(c) cases are ultimately resolved through negotiation or Tax Court proceedings when the initial IRS determination is unfavorable.

How Brightside Tax Relief Can Help

Separation of Liability Relief is one of the most powerful tools available to divorced and separated spouses facing joint tax debt — but it is also one of the most procedurally demanding. The allocation analysis requires documentation. The actual knowledge limitation requires a specific factual response. The two-year filing deadline creates urgency. And the entire process unfolds while an ex-spouse is being notified and given the opportunity to object.

At Brightside Tax Relief, we guide clients through every step of the Section 6015(c) process: analyzing the deficiency allocation, gathering the documentation needed to establish the proper split, responding to IRS requests for information, and representing clients in Tax Court when an administrative denial requires judicial review. If you are divorced, separated, or estranged from a former spouse and the IRS is holding you responsible for a joint tax liability you believe should be the other spouse's responsibility, contact Brightside Tax Relief today for a free consultation. Understanding your rights is the first step toward resolving this the right way.