Picture this: a small US partnership with two American founders, all domestic business, zero foreign customers, no foreign bank accounts, and absolutely nothing exotic on the balance sheet. Tax season rolls around, and the CPA hands over a Form 1065 packet that's three times thicker than last year. Why? A pair of forms with intimidating names — Schedule K-2 and Schedule K-3 — that the IRS introduced for tax year 2021 and that, on paper, look like they only apply to multinational entities. In practice, they have caught countless purely domestic partnerships and S-corps in their net.
If you own, advise, or prepare returns for a pass-through entity, you need to understand these schedules — not because they are conceptually difficult, but because the exception rules are where most of the work happens. The IRS expanded the carve-outs again in 2025, and the calendar deadlines you have to hit to use those carve-outs in tax year 2025 (filed in 2026) are unforgiving. Miss the January 15 notification window, and you're filing the full schedules anyway. Miss the answer to a K-3 request received by February 15, and you're filing penalties.
This guide walks through what K-2 and K-3 actually require, who has to file them, the three escape hatches the IRS has built in, the calendar of dates you cannot miss for 2026 filings, and the penalty math that makes compliance worth the spreadsheet time.
What Schedules K-2 and K-3 Actually Are
Before 2021, partnerships and S-corps reported items of "international tax relevance" on a handful of free-form footnotes attached to each partner's Schedule K-1. There was no standard format. One CPA might attach a one-page narrative; another might attach a fifteen-page spreadsheet. The IRS could not machine-read any of it, and partners trying to claim foreign tax credits on their personal returns had to interpret whatever their entity had decided to send.
Schedule K-2 (entity-level) and Schedule K-3 (partner-level) replaced that mess with a single standardized format. They are extensions of Schedules K and K-1, respectively.
Schedule K-2 is a multi-part schedule attached to the entity's Form 1065 (partnership) or Form 1120-S (S-corp). It reports the entity's aggregate foreign source income, foreign taxes paid, foreign source deductions, foreign branch income, GILTI inclusions, Subpart F income, and a dozen other categories of cross-border items. Depending on the entity's activities, K-2 can be anywhere from a few pages to fifty.
Schedule K-3 is the partner-level mirror. Each partner or shareholder gets their own K-3 showing their distributive share of every K-2 line. The partner uses that K-3 to fill out their personal Form 1116 (foreign tax credit), Form 5471, Form 8621, or other international compliance forms on their own return.
The whole architecture has the look and feel of standardization, but the side effect was that every pass-through entity now had to evaluate whether it had any international items at all — even if it didn't.
Why Purely Domestic Partnerships Got Pulled In
Here is the trap that surprised so many practitioners in 2022 and 2023: the original instructions required Schedules K-2 and K-3 to be filed if any partner could potentially need international information to complete their own return — even if the partnership itself was purely domestic.
The example the IRS gave was devastating: imagine a US partnership that earns 100% of its income in Ohio, pays zero foreign taxes, and has no foreign assets. If one of the partners happens to own foreign stock in their personal portfolio and pays foreign withholding tax on dividends, that partner needs to file Form 1116. To file Form 1116 correctly, they need to apportion all their deductions — including their share of partnership-level deductions — between US and foreign source income. Therefore, the partnership had to give them the data, which meant filing K-2 and K-3 even though the entity had no foreign anything.
Practitioners revolted. Software vendors couldn't keep up. The IRS issued a series of FAQs, then a "domestic filing exception" for 2022, then expanded it for 2023, then expanded it again for 2024 and beyond. The current rules (effective for tax year 2024 returns filed in 2025, and continuing for tax year 2025 returns filed in 2026) are noticeably friendlier — but you have to hit specific milestones to use them.
The Three Escape Hatches in 2026
For tax year 2025 (returns filed in 2026), three distinct exceptions can spare a pass-through entity from completing some or all of Schedules K-2 and K-3.
1. The Domestic Filing Exception
This is the workhorse exception that most small-to-mid-size domestic partnerships and S-corps will use. To qualify, the entity must meet four conditions:
Condition 1 — No or limited foreign activity. The entity has either (a) no foreign activity at all, or (b) "limited foreign activity," defined as passive category foreign income that generated no more than $300 of creditable foreign income taxes, where those taxes were reported to the entity on a payee statement (such as a brokerage 1099).
Condition 2 — Direct partners or shareholders are all US persons. Every direct partner or shareholder must be a US citizen, a resident alien individual, a domestic estate, a domestic grantor trust whose grantor is a US person, a domestic non-grantor trust where every beneficiary is a US citizen or resident alien, an S corporation with only US individual shareholders, or a single-member disregarded LLC owned by a US person. As of the July 2025 IRS update, the exception now also explicitly covers multi-owner S corporations — a significant expansion.
Condition 3 — Partner notification by January 15. The entity must notify every partner or shareholder, at the latest when the K-1 is furnished, that no Schedule K-3 will be provided unless requested. For calendar-year filers in 2026, this notification deadline is January 15, 2026. The notification can be a separate letter or an attachment to the K-1 itself.
Condition 4 — No K-3 request by the 1-month date. If any partner requests a K-3 by the "1-month date" (one month before the entity's unextended return due date), the exception is blown and the entity must file K-2 and K-3. For calendar-year partnerships filing Form 1065, the unextended due date is March 15, 2026, making the 1-month date February 15, 2026.
All four conditions must be met. Miss any one, and the full K-2/K-3 filing is back on the table.
2. The New Small Entity Exception (Added 2024, Continuing 2026)
The IRS added a brand-new exception starting with tax year 2024 returns. A partnership or S corporation is exempt from K-2 and K-3 filing entirely if both of these are true:
- Total receipts for the tax year are less than $250,000, and
- Total assets at the end of the tax year are less than $250,000.
This is a gross receipts test, not net. And critically, this small entity exception does not require the partner notification or the 1-month rule — it stands on its own. For a genuinely small pass-through with modest revenue and a thin balance sheet, this is the cleanest exit.
A subtle point: if your entity is right around the $250,000 thresholds, you cannot rely on this exception. You'll need either the domestic filing exception (with its January and February deadlines) or full compliance.
3. The Partner-Specific Form 1116 Exemption
A separate, narrower carve-out exists under Form 1116 rules: if every partner is exempt from filing Form 1116 (for example, because their total foreign taxes paid are below the $300/$600 de minimis individual threshold and they elect not to file Form 1116), the entity may be excused from completing Parts II and III of K-2 and K-3 for those partners. This is rarely used as the primary exception because the entity must have actual knowledge or notice of every partner's Form 1116 status — and most entities can't get that.
The Calendar That Matters for 2026 Filings
For calendar-year partnerships and S-corps filing tax year 2025 returns in 2026, three dates anchor the K-2/K-3 compliance plan:
- January 15, 2026 — Deadline to notify partners or shareholders that no K-3 will be furnished unless requested. Skip this and you cannot use the domestic filing exception, even if you meet every other condition.
- February 15, 2026 — The 1-month date for calendar-year partnerships (Form 1065). If any partner submits a K-3 request on or before this date, you must file K-2 and K-3 in full and furnish K-3 to the requesting partner.
- March 15, 2026 — Form 1065 and Form 1120-S due date (unextended). Schedules K-2 and K-3, if required, are filed with the return.
For fiscal-year entities, shift the dates accordingly. The 1-month date is always one month before the unextended due date of the entity's return, regardless of any extension granted.
There is one more important wrinkle: even if a partner sends a K-3 request after February 15, the entity is not legally required to provide it for that year. Many partnerships choose to provide K-3 informally anyway to preserve the relationship — but the legal obligation ends at the 1-month date.
Penalties: Why You Don't Want to Get This Wrong
The IRS treats failure to file Schedules K-2 and K-3 the same way it treats failure to file a complete Form 1065 or Form 1120-S. The penalty math is per-partner, per-month, and it adds up quickly.
Late filing or incomplete filing of Form 1065/1120-S (which now includes the K-2 schedules) carries a penalty of approximately $245 per partner or shareholder, per month, for up to twelve months. A six-partner partnership that files three months late is looking at $4,410 in entity-level penalties before the K-2 issue is even considered separately.
Failure to furnish a correct Schedule K-1 (which now includes K-3) to a partner carries a separate penalty under IRC §6722 — generally $310 per partner for 2026 filings, indexed annually for inflation.
Failure to provide K-3 after a timely request is treated as an incomplete K-1, exposing the entity to the same $310 per-partner penalty.
For a five-partner domestic partnership that thought it qualified for the exception, missed the January 15 notification, and is later assessed both penalties, the total exposure can easily exceed $3,000 for what was effectively a paperwork lapse.
Reasonable cause relief is available under IRC §6724 for first-time or genuinely inadvertent failures, but the entity has to make the case — and the IRS has signaled that "we didn't know" is not by itself reasonable cause, since K-2 and K-3 have been in effect since 2021.
Where Most Entities Trip Up
Across thousands of practitioner accounts and IRS guidance updates, four mistakes dominate.
1. Treating the notification as optional. Some entities figure they will just "wait and see" whether any partner requests a K-3 before deciding whether to file. That doesn't work — the notification by January 15 is a precondition of the exception. Without notification, even if no partner ever requests anything, the exception is unavailable.
2. Missing limited foreign activity. A partnership might think it has "no foreign activity" because it has no foreign customers, no foreign offices, and no overseas operations. But a single foreign-source dividend from a $10,000 brokerage holding — or one foreign tax withheld on a corporate bond — is technically foreign activity. As long as the foreign tax stays under $300 and the income was reported on a 1099 or similar payee statement, the entity is still within "limited foreign activity." Above that, it has full foreign activity and the exception is unavailable.
3. Foreign partners hidden in ownership chains. The domestic filing exception requires direct owners to be US persons. A foreign individual who owns through a US LLC is still a foreign partner for these purposes if the LLC is a passthrough. And an S corporation cannot be a partner if it has any non-US-individual shareholders. Get the chain wrong and the exception is lost.
4. Failing to gather K-3 data anyway. Even if you fully qualify for the exception, if a partner requests K-3 by February 15, you have to produce one. That means you need to have the underlying data ready — country-by-country foreign source income, foreign taxes by category, asset and gross income apportionment — regardless of whether you ultimately file. Many practitioners now prepare a draft K-3 worksheet in January as insurance, just in case a request arrives.
A Practical Action Plan for 2026
For a domestic partnership or S corporation working through tax year 2025:
- Inventory foreign activity by December. Pull every 1099-DIV, 1099-INT, brokerage statement, and K-1 received from other entities. Identify foreign source income and foreign tax line items. If total foreign tax exceeds $300, you have full foreign activity.
- Verify partner status. Confirm each partner or shareholder qualifies under the domestic filing exception (or that your entity passes the $250,000/$250,000 small entity test).
- Send the partner notification by January 15, 2026. Use a written notice — either standalone or attached to draft K-1 — stating that the entity does not expect to furnish Schedule K-3 unless requested by the 1-month date of February 15, 2026.
- Maintain workpapers. Even if you expect to use the exception, prepare the source data needed to complete K-2 and K-3 in case a partner request lands on February 15. This is cheaper than scrambling in late February.
- Track requests. Document every K-3 request received and the date received. If even one partner requests by the deadline, file in full.
- File timely. Submit Form 1065 or 1120-S — with or without K-2 and K-3 attached, depending on outcome — by March 15, 2026 (or with extension).
The Broader Lesson: International Reporting Has Moved Downstream
Schedules K-2 and K-3 reflect a broader IRS trend: pushing international tax reporting compliance from the largest multinationals down to mid-market and smaller entities. The forms that used to be the exclusive province of multinational tax departments — country-by-country sourcing, foreign tax credit limitation categories, GILTI mechanics — now appear, in simplified form, on the desk of any CPA with a partnership client that owns a single foreign mutual fund.
The good news: the IRS has been responsive to practitioner feedback. The exceptions in 2026 are meaningfully easier to use than they were in 2022. The bad news: the deadlines are real, the penalties are per-partner, and the rules are unlikely to soften further. Treat K-2 and K-3 as a recurring January calendar item, not a March surprise.
Keep Your Books International-Ready From Day One
If your partnership or S corporation has any chance of foreign income — even a tiny brokerage dividend — your books need to track foreign source items separately, by country and by category, from the moment they hit your ledger. Waiting until tax season to figure out which transactions were foreign-source is how partnerships end up rebuilding twelve months of records in February.
Beancount.io is plain-text accounting designed for exactly this kind of granular, auditable, multi-currency tracking. Every transaction is queryable by tag, metadata, and source, so foreign-source income, foreign withholding, and country-level activity are easy to slice when K-2 and K-3 season arrives. No vendor lock-in, no black-box ledger — just clean, readable accounting records that survive audit. Get started for free and see why developers and finance teams are switching to plain-text accounting.