Backup Withholding on Card and Marketplace Payments

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The Internal Revenue Service, writing for the Treasury Department, published 91 FR 51391 on August 10, 2026. These regulations are effective on August 10, 2026. They govern backup withholding on reportable payments with respect to third party network transactions, and they apply today to third party settlement organizations and to the preparers who reconcile the information return-K and Form 945.

What is in force now?

The DATES section of 91 FR 51391 states: “Effective date: These regulations are effective on August 10, 2026.” The notice carries RIN 1545-BR80 and amends 26 CFR Part 31. Current regulation text for that part is on the eCFR.

The same DATES block points to applicability dates in §the applicable section(a)-1(e) and the applicable section(b)(3)-5(e). Those provisions apply with respect to payments made in calendar years beginning after December 31, 2024, according to the amendatory text in 91 FR 51391. The regulations are therefore in force now, and they reach payments already made in calendar years after that statutory line.

The obligation that applies today is backup withholding on reportable third party network transactions when a condition for withholding exists, in the amount the regulations describe, deposited and reported on Form 945. Crossing a gross-payment figure, by itself, is not the withholding trigger. The trigger is a backup-withholding condition — in the notice's worked example, a payee that does not provide its taxpayer identification number — applied to payments that are reportable under section 6050W.

This page is written from a sealed index of 1086 federal rules from 11 agencies, published September 1, 2023 – September 1, 2026. It is a snapshot, not a substitute for the current 26 CFR Part 31 text on the eCFR.

What does the rule require?

The document contains final regulations governing backup withholding on reportable payments with respect to third party network transactions, according to the abstract in 91 FR 51391. The final regulations reflect recent changes to the statutory law that affect the backup withholding requirements for third party settlement organizations who make payments in settlement of third party network transactions.

Under revised the applicable section(a)-1, a payor must deduct and withhold an amount equal to the product of the fourth lowest rate of tax applicable under section 1(c) of the Code and a reportable payment if a condition for withholding exists, according to the amendatory text in 91 FR 51391. The notice does not print that rate as a percentage. The rate is the product described in that sentence. A preparer who invents a different percentage is not quoting the rule.

The amount subject to backup withholding is the amount subject to reporting under section 6050W, according to revised the applicable section(b)(3)-5(b). For payments in settlement of third party network transactions, that amount is determined with regard to the exception for de minimis payments by third party settlement organizations in section 6050W(e). A payment is treated as a reportable payment only if, during the calendar year, the aggregate number of transactions with respect to the participating payee exceeds the number of transactions specified in section 6050W(e)(2) and the aggregate amount of all reportable payment transactions with respect to that participating payee exceeds the dollar amount specified in section 6050W(e)(1).

Example 1 in 91 FR 51391 is the operational picture. Platform A is a third party settlement organization. Y is a participating payee. A solicits a TIN; Y does not provide its TIN. During calendar year 2026, A makes 201 payments that total a dollar amount the rule does not restate here,the applicable section. A must backup withhold on the entire amount of the 201st transaction because that transaction caused Y to exceed the de minimis reporting threshold for calendar year 2026 of 200 transactions and a dollar amount the rule does not restate here in gross payments. The missing TIN is the withholding condition. The 200 / a dollar amount the rule does not restate here line is when the payment becomes a reportable payment. Withholding follows the TIN-matching failure, not the gross-payment threshold standing alone.

Example 2 through Example 4 then show a carryover: if one or more payments in the preceding calendar year were reportable payments, the payor must backup withhold on each payment in the current year even when that year's volume is under the de minimis line, until a year with no reportable payments breaks the chain, according to paragraph (b)(3) and the examples in 91 FR 51391.

The Paperwork Reduction Act discussion in the same notice identifies Form 945, Annual Return of Withheld Federal Income Tax, as the form that carries the backup-withholding information collection. the information return-K, Payment Card and Third Party Network Transactions, is the information return the preamble discusses for the underlying payments. A settlement entity that withholds and never lands the tax on Form 945 has an incomplete reporting path.

The preamble also states that the taxability of payments and the reportability of income on an income tax return are not determined by whether the IRS or the taxpayer receives a the information return-K, or by whether backup withholding is required with respect to a third party network transaction, according to 91 FR 51391. Missing a form does not make the income nontaxable.

Where do accounting firms commonly fall short?

The pattern that shows up in client files is treating the the information return-K dollar line as if it were the backup-withholding switch. The regulations in 91 FR 51391 do not work that way. A payee over the de minimis reporting line with a complete TIN is on an information-return path. A payee without a TIN, once the payment is reportable, is on a backup-withholding path. Collapsing those two into “we issued a an information return-K, so we are done” is the miss.

A second pattern is ignoring the prior-year carryover in paragraph (b)(3). Example 2 of 91 FR 51391 keeps withholding on in a year with many payments totaling a dollar amount the rule does not restate here,the applicable section because the preceding year was reportable. A workpaper that only tests the current-year 200 / a dollar amount the rule does not restate here line will under-withhold.

A third pattern is depositing nothing because “the platform should have withheld.” The regulations address third party settlement organizations who make payments in settlement of third party network transactions. A preparer with marketplace, gig-platform, or card-processing clients still has to know which entity is the payor, whether a TIN was solicited, and whether Form 945 was filed. The rule does not say that a payee's income-tax return cures a payor's withholding miss.

This page does not invent enforcement statistics. The rule does not say a penalty dollar amount for this update. Where 91 FR 51391 is silent on a figure, the figure is not here.

Related accounting pages on this site include the qualified-tips tax deduction guide, catch-up contributions, and information reporting and transfer for valuable consideration. Those pages do not replace 26 CFR Part 31.

What self-audit can a firm run now?

The self-audit is a payee-by-payee file, not a firm-wide slogan. Each client that is a third party settlement organization, or that receives a the information return-K as a participating payee, maps to TIN status, transaction count, dollar total, prior-year reportable status, withheld tax, and Form 945.

1. List every client engagement that involves a third party network transaction, a the information return-K, or a platform payout, then name the payor and the participating payee as 91 FR 51391 uses those terms.

2. For each participating payee, record whether a TIN was solicited and whether it was provided. That is the withholding-condition column, not the dollar column.

3. Compare current-year transaction count and gross amount to the section 6050W(e) de minimis line illustrated in Example 1 (200 transactions and a dollar amount the rule does not restate here for calendar year 2026).

4. Check the preceding calendar year. If any payment that year was a reportable payment, paragraph (b)(3) keeps withholding on, according to 91 FR 51391.

5. Where a condition for withholding exists and the payment is reportable, confirm the withheld amount is the product of the fourth lowest rate of tax applicable under section 1(c) and the reportable payment, and that the tax is on Form 945.

6. Route any file that has a missing TIN, a prior-year reportable flag, and no Form 945 to the responsible preparer. Do not treat a an information return-K as the withheld-tax return.

Drake Tax is the professional preparation system many firms already use to complete federal returns and information-return workpapers. QuickBooks Online is the bookkeeping system many of the same clients already use to record payouts, vendor records, and TIN fields. Neither product is named in 91 FR 51391. The operational question is whether the payee record in QuickBooks Online still lacks a TIN while Drake Tax is being asked to prepare a an information return-K with no Form 945 path.

The rule does not say how a firm must configure Drake Tax or QuickBooks Online. The rule does not say that a software label of “an information return-K vendor” is a TIN match. Those tools can hold the payee, the payout, and the return. A qualified professional decides whether backup withholding was required.

How does a firm operationalize the obligation at volume?

Reconcile the client book against the change: each client engagement maps to the forms, elections, and filing dates the rule touches. US Tech Automations flags engagements whose workpapers still reflect the superseded treatment and routes the review to the responsible preparer.

That is a flag-and-route job. US Tech Automations can mark a QuickBooks Online payee with no TIN whose current-year or prior-year totals make the payment reportable, and send that engagement to the Drake Tax preparer who owns the Form 945. It cannot compute a filing position, cannot select the section 1(c) product as a substitute for professional judgment, and cannot certify that withholding was correct.

The useful volume pattern is one source event per participating payee. TIN status, current-year de minimis, prior-year reportable status, and Form 945 are separate fields. Flattening them into “an information return-K issued” is how a firm misses Example 2 carryover or withholds on a payee who provided a TIN.

US Tech Automations can keep those fields visible and escalate a missing owner. A qualified professional still applies 26 CFR Part 31. The software routes; the preparer concludes.

What questions do preparers still ask?

Is this rule already in effect?

Yes. These regulations are effective on August 10, 2026, and they apply with respect to payments made in calendar years beginning after December 31, 2024.

What is the withholding rate?

A payor must deduct and withhold an amount equal to the product of the fourth lowest rate of tax applicable under section 1(c) of the Code and a reportable payment if a condition for withholding exists, according to 91 FR 51391. The notice does not print that product as a percentage.

Does crossing a dollar amount the rule does not restate here of platform payments, by itself, start backup withholding?

No. Example 1 of 91 FR 51391 withholds because Y did not provide its TIN and then exceeded the de minimis reporting threshold. Withholding follows the TIN-matching failure, not the gross-payment threshold standing alone.

Which form reports the withheld tax?

The Paperwork Reduction Act section of 91 FR 51391 names Form 945, Annual Return of Withheld Federal Income Tax. the information return-K reports the underlying third party network transactions; it is not the withheld-tax return.

If no the information return-K issued, is the income nontaxable?

No. The preamble states that taxability is not determined by whether a the information return-K is received or by whether backup withholding is required, according to 91 FR 51391.

Can software decide that backup withholding was not required?

No. A workflow can flag a missing TIN or a missing Form 945. A qualified professional applies 26 CFR Part 31 to the file.

Key Takeaways

• 91 FR 51391, RIN 1545-BR80, amends 26 CFR Part 31 and is effective on August 10, 2026.

• The withholding amount is the product of the fourth lowest rate of tax applicable under section 1(c) and a reportable payment if a condition for withholding exists.

• Example 1 withholds because the payee did not provide a TIN and then exceeded 200 transactions and a dollar amount the rule does not restate here; the TIN failure is the condition, not the dollar line alone.

• Form 945 is the return named for the withheld tax; the information return-K is the information return for the payments.

• The notice does not publish a penalty dollar amount for this update; missing withholding is still a payor miss.

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Every date, citation, RIN, CFR reference, and figure in these posts is copied verbatim from the Federal Register and eCFR as of the snapshot date. Nothing is estimated, modeled, or extrapolated. This is not legal or tax advice.

Source: Federal Register / eCFR

This page is for informational purposes only. It is not legal or tax advice and does not create an attorney-client relationship. Read 91 FR 51391 and the current text of 26 CFR Part 31, and consult a qualified professional about a particular payor, payee, the information return-K, or Form 945.

Last reviewed: August 10, 2026

The exception path is the agentic workflow layer.