What it means
Professionals like doctors, lawyers, and consultants often incorporate their practices. The corporation then bills clients and pays its owner a salary, which is perfectly ordinary, until the tax law asks what kind of corporation it is.
A personal service corporation, in US tax terms, meets two tests: its principal activity is performing personal services in fields like health, law, engineering, accounting, or consulting, and those services are substantially performed by employee-owners who hold the stock. The label matters because the tax code treats these entities harshly.
The rules exist to stop professionals from sheltering income inside a corporate shell instead of taking it as personal earnings. The sting was historically the tax rate.
Before the 2017 US tax reform, personal service corporations paid a special flat 35% on all taxable income while ordinary corporations enjoyed lower graduated brackets, whereas the corporate rate is now a single flat rate set by current tax law. Other restrictions still apply: these corporations are generally required to use a calendar tax year to match their owners, and they face limits on deducting certain passive losses.
The IRS lays out the definition and tests in Publication 542 on corporations, including the ownership and activity thresholds that decide whether the rules bite. The classification risk runs both ways.
Companies that drift into personal service status through ownership changes can face unexpected reclassification, while genuine service firms must plan around the restrictions from day one. For a non-finance reader, the concept answers a common question: why can't the consultant next door just incorporate and pay corporate tax rates?
Because when the corporation is really a person in a suit, the tax law insists on treating it like one. The salary question dominates practice in this area.
Owners tempted to minimise salary and leave profit in the company discover that the risk of accumulated earnings penalties usually erases the benefit. Reasonable compensation runs the other way too.
Paying excessive salaries to zero out corporate income draws IRS attention of its own, so the planning sweet spot is narrow and heavily documented.
In practice
Real-world examples.
Example
A three-doctor medical practice corporation is classified as a personal service corporation because its owners perform substantially all the services. The classification follows the facts of who does the work and who owns the shares.
Example
A consulting firm's attempt to shift income into the corporation at low cost collapses when the calendar tax year requirement and the accumulated earnings rules are applied.
Example
An engineering company avoids the classification after ownership spreads to outside investors who perform no services, failing the ownership test.
Formula
Calculation
Qualification requires two tests: the activity test, where the principal activity involves personal services in qualifying fields, and the ownership test, where those services are substantially performed by employee-owners who hold the stock. The exact thresholds depend on which definition in the tax code applies, so check IRS Publication 542 and the relevant code section.
Worked example of the activity test. A fictional architecture firm bills $2,000,000, of which $1,900,000 comes from design services and $100,000 from selling plan templates. The design share is $1,900,000 / $2,000,000 = 95%, a strong sign that substantially all activity is qualifying services, although the legal test looks at the activities and the time employees spend on them.
Worked example of the ownership test. If the three architects who perform the services own 100% of the stock, the services are performed by the people who hold it. If outside investors who perform no services bought 40% of the stock, the ownership picture would change materially and the firm should seek advice on its classification.Case study
Seen in the real world.
This case study is fictional and illustrative. Three made-up architects incorporate their practice and have a good year, billing $2 million. Their accountant asks whether they should retain $200,000 of profit in the company to fund expansion, taking advantage of corporate tax rates. The answer comes with warnings.
As a personal service corporation, the firm must use a calendar tax year, faces limits on certain passive losses, and risks the accumulated earnings tax if it retains earnings purely to dodge personal tax. The partners instead pay themselves reasonable salaries, deduct genuine business costs, and retain only what the expansion plan justifies on paper. When a neighbouring consultancy is audited and hit with reclassification plus penalties for aggressive salary suppression, the architects' boring compliance suddenly looks like the better design.
Watch out
Common mistakes.
- Assuming any incorporated professional practice escapes personal tax rates; the personal service corporation rules exist precisely to prevent that shelter.
- Forcing a fiscal year for tax convenience; these corporations are generally locked to the calendar year unless they meet narrow exceptions.
- Ignoring the ownership test; stock held by the service-performing employees is what triggers the classification, so ownership restructuring changes the answer.
Questions
People also ask.
What is a personal service corporation?
A corporation whose principal activity is performing personal services in fields like health, law, or consulting, substantially performed by employee-owners holding its stock.
How is it taxed?
At the corporate rate set by current tax law, with additional restrictions on tax years and certain deductions, per IRS Publication 542.
Why do the rules exist?
To stop professionals sheltering personal earnings inside a corporate wrapper; the code treats the corporation as an extension of its owner-performers.
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