What Is a Common Paymaster and How Does It Work?

A common paymaster is one corporation within a group of related companies that takes over payroll for employees who work for two or more of those companies at the same time. The arrangement lets the group apply federal payroll tax caps once per employee across all the related employers, instead of restarting the cap at every entity that cuts a check. For 2026, that means the Social Security taxable wage base of $184,500 is tracked once per concurrent employee.¹ The same single-cap treatment applies to the $7,000 Federal Unemployment Tax Act (FUTA) wage base and to the $200,000 Additional Medicare Tax withholding threshold.²

How the Arrangement Works

When an employee splits time between two or more related corporations during the same calendar quarter, each corporation is technically its own employer with its own payroll tax obligations. Without a common paymaster, every entity separately applies the Social Security wage base to the wages it pays, so the combined withholding can climb past what a single employer would owe on the same total salary. The employee can end up overpaying their share and having to claim it back on their personal return.

Designating one related corporation as the common paymaster fixes that. Under 26 U.S.C. § 3121(s), the paymaster disburses all wages to the concurrent employees on behalf of the group, and each related corporation is then treated as having paid only the wages it actually funded. The paymaster is treated as the single employer for wage-base purposes, so the Social Security cap, the FUTA cap, and the Additional Medicare Tax threshold each apply once.³

The paymaster actually has to cut the checks. If the related corporations keep paying employees separately, each one remains independently responsible for its own payroll taxes, and the single-cap benefit disappears.⁴

Which Corporations Count as Related

Not every corporate group qualifies. The Treasury regulations at 26 CFR § 31.3121(s)-1 set four tests, and the corporations only need to satisfy one of them at any point during a calendar quarter to be treated as related for the whole quarter.⁵

Controlled group. The corporations belong to a controlled group under IRC § 1563, but with a lower ownership bar. Where § 1563 normally requires at least 80 percent ownership, the common paymaster rule substitutes “more than 50 percent.” This covers parent-subsidiary chains and brother-sister structures where five or fewer individuals collectively own more than 50 percent of each corporation.
Board or voting control. At least 50 percent of one corporation’s board of directors also sits on the other corporation’s board, or the people who hold 50 percent or more of the voting power to select those board members hold the same power in both corporations. This is the test most relevant to non-stock entities like nonprofits.
Common officers. At least 50 percent of one corporation’s officers simultaneously serve as officers of the other. Professional services firms and healthcare systems where executives wear multiple hats often qualify under this test.
Shared workforce. At least 30 percent of one corporation’s employees are concurrently employed by the other corporation.

These thresholds are lower than many payroll teams expect. A parent company owning 51 percent of a subsidiary’s voting stock satisfies the first test. If a group cannot meet any of the four, the IRS will not recognize the arrangement, and each entity must withhold and deposit payroll taxes independently.

Which Taxes Get the Single-Cap Treatment

Social Security (OASDI)

Social Security tax is 6.2 percent on both the employer and the employee, applied only to wages up to the annual base. For 2026, that base is $184,500. Under a common paymaster, once the concurrent employee’s combined wages from all related corporations reach $184,500, the paymaster stops withholding the employee’s share and the employers stop owing the match. An employee hitting $184,500 in 2026 would contribute $11,439, and the employer side would match that amount.¹

Additional Medicare Tax

Regular Medicare tax is 1.45 percent on both sides with no wage cap, so a common paymaster does not reduce total Medicare tax. The Additional Medicare Tax is different. Employers must withhold an extra 0.9 percent on wages above $200,000 in a calendar year, and under the paymaster arrangement the wages from all related corporations combine when tracking that $200,000 threshold. An employee earning $120,000 from one entity and $110,000 from another crosses the line at combined wages, and the paymaster begins withholding the extra 0.9 percent.⁶ Without a common paymaster, neither entity’s wages would hit $200,000 on their own, and the withholding obligation would fall through until the employee filed their individual return.

FUTA

Federal unemployment tax applies to the first $7,000 of each employee’s wages at a gross rate of 6.0 percent, reduced to an effective 0.6 percent for most employers through the standard 5.4 percent credit.² Under 26 U.S.C. § 3306(p), the common paymaster applies a single $7,000 cap per concurrent employee. The dollar savings per employee are modest, but a group with hundreds of concurrent workers gets meaningful administrative simplification.

What Concurrent Employment Actually Requires

This is where most arrangements run into trouble. The IRS defines concurrent employment as the contemporaneous existence of an employment relationship between an individual and two or more related corporations. The employee has to perform services that benefit each employing corporation, not just the corporate group in the abstract, and has to receive remuneration from each one.⁵

An employee who transfers from Corporation A to Corporation B with no plans to return is not concurrently employed, even if both corporations are related and use the same paymaster. The relationship with A ended before the one with B began. Similarly, an employee who is on a second corporation’s payroll in name only, without performing real services for it, is presumed not to be employed by that corporation.⁴

Timing matters at the transaction level too. The single-cap treatment only covers wages disbursed while the employee is concurrently employed by the paymaster and at least one other related corporation. A bonus paid in December for work done entirely before the concurrent arrangement started would not qualify.

State Unemployment Tax Does Not Automatically Follow

Federal law creates the common paymaster framework for FICA and FUTA, but state unemployment insurance programs are administered separately. Some states recognize common paymaster treatment, others reject it, and others impose their own conditions. Pennsylvania, for instance, prohibits common paymaster reporting for state unemployment and requires each legal entity to keep its own separate employer account.

State unemployment rates are experience-rated based on each employer’s claims history, so letting one entity report for the whole group would distort the rates. State SUTA wage bases also range widely, from the federal floor of $7,000 up past $78,000 depending on the state. A payroll team that assumes the federal election carries over to the state level risks penalties and back taxes in every state where concurrent employees work. Check each state’s unemployment agency for its position before implementing the arrangement.

Setup, Filings, and Records

Getting the arrangement in place takes more than an informal understanding between related corporations. Several pieces need to be established before the paymaster files its first return.

A board resolution or written agreement designating which corporation will serve as the common paymaster, with an effective date and the related corporations covered.
Documentation proving related status. Stock ledgers, articles of incorporation, board rosters, or officer lists showing the group meets at least one of the four tests, maintained for every quarter the arrangement is in effect.
Concurrent employment records. Time records, job descriptions, or service agreements showing each employee actually performed work for multiple entities during the same period. Nominal inclusion on a second payroll will not survive an audit.
Payroll allocation data breaking down how much of each concurrent employee’s wages is attributable to each corporation, both for tax filing and for calculating each entity’s share of liability if something goes wrong.

The paymaster files Form 941 quarterly under its own Employer Identification Number, reporting combined wages, tips, and other compensation paid to all concurrent employees across the related group.⁴ It also files Form 940 annually for the consolidated FUTA obligation. At year-end, the paymaster issues a single Form W-2 to each concurrent employee reflecting total earnings from all related entities and total taxes withheld under the paymaster’s EIN.⁷ Each related corporation still needs its own EIN on file, even though the paymaster handles the reporting.

Joint and Several Liability

The liability rules here are less forgiving than many corporate groups expect. If the common paymaster fails to deposit or pay the required FICA taxes, it remains on the hook for the full unpaid balance. Each of the other related corporations is then jointly and severally liable for its appropriate share of the shortfall.⁷

In practical terms, the IRS can collect from any corporation in the group, but no single related corporation’s exposure exceeds what it would have owed on the wages it funded had there been no common paymaster. The liability applies whether or not the employee’s share was actually withheld from wages, so a paymaster that collected withholding but failed to deposit it creates exposure for every related entity in the group.⁵

What Draws IRS Scrutiny

The IRS has published circumstances that flag common paymaster arrangements for closer review. Examiners look for payroll funds moving between related entities without clear documentation that the transfers represent wages. They also watch for a corporation reporting salaries and wages on its books but filing no employment tax returns, or filed returns that do not reconcile to the payroll accounts. For tax-exempt organizations, a 501(c)(3) filing Form 940 on behalf of a related organization classified under a different subsection is a known audit indicator.⁴

The IRS also watches for arrangements that may mask private benefit or inurement, particularly among nonprofits. If an outsized amount of wages is being channeled to another entity, or if fund transfers lack documentation tying them to actual payroll, examiners will escalate. Each organization remains a separate legal entity regardless of the arrangement, and the structure cannot be used to blur the financial independence of the participating corporations.⁴

During an examination, the IRS will verify that the corporations are related under at least one of the four tests, that the paymaster is itself a member of the related group, that employees actually received their wages through the paymaster, and that those employees were genuinely concurrently employed. Failing any of those checks unwinds the arrangement and leaves each corporation independently liable for the payroll taxes it should have been paying all along.

1
Social Security Administration. Contribution and Benefit Base
2
Office of the Law Revision Counsel. 26 U.S. Code 3306 – Definitions
3
Office of the Law Revision Counsel. 26 U.S.C. 3121 – Definitions
4
Internal Revenue Service. Common Paymaster
5
eCFR. 26 CFR 31.3121(s)-1 – Concurrent Employment by Related Corporations With Common Paymaster
6
Internal Revenue Service. Questions and Answers for the Additional Medicare Tax
7
eCFR. 26 CFR 31.3121(s)-1 – Concurrent Employment by Related Corporations With Common Paymaster