Understanding Patent Restriction Requirements

For many patent applicants, the first communication they receive from the United States Patent and Trademark Office (USPTO) is not a “yes” or a “no” on their invention. It is, rather, a pick-one. This is the restriction requirement. While it can feel like a bureaucratic hurdle designed to double your filing fees, the restriction requirement is a fundamental part of patent office management and legal strategy.

What is a Restriction Requirement?

Under 35 U.S.C. § 121, if the USPTO determines that a single patent application contains “two or more independent and distinct inventions,” the Examiner can require the applicant to restrict the application to just one of those inventions.¹

The Two-Pronged Test

Restrictions are not issued on a whim. Each must satisfy two conditions:

1. Independent and Distinct: the inventions must be technically different (e.g., a specific chemical compound vs. a machine that happens to use that compound).
2. Serious Burden: the Examiner must show that searching and examining both would be a serious burden on the USPTO (e.g., they require searching different classes or art fields).

Why Does the USPTO Do This?

• Administrative Efficiency: Examiners are specialized. If one application covers a drone engine and a cloud-based delivery software, it would require two different specialists to review it.
• Revenue Management: the USPTO is funded by fees. By forcing distinct inventions into separate applications (divisionals or continuations), the USPTO ensures it is paid for the work required to examine each unique advancement.
• Clearer Prosecution: it prevents a muddled file wrapper where the prior art for one invention overlaps confusingly with the second.

Restriction vs. Unity of Invention: The Global Perspective

If you file internationally via the Patent Cooperation Treaty (PCT) or in jurisdictions like the European Patent Office (EPO), you will encounter the principle of unity of invention.

While they sound similar, the legal threshold is quite different:

Feature	Restriction	International Unity of Invention
Legal Basis	35 U.S.C. § 1212	PCT Rule 13 / EPO Art. 82
Standard	Inventions must be independent and distinct	Inventions must share a special technical feature (STF)
Burdens	Focuses on the Examiner’s workload	Focuses on the technical relationship between claims
Timing	Often issued before any substantive search	Often issued after the search identifies the special technical feature

The unity standard is generally considered more applicant-friendly. Under unity, as long as your different embodiments share a common inventive spark (i.e, the STF) that makes them new over the prior art, and therefore, you can keep them in one application. The USPTO’s restriction standard is much narrower, often splitting applications that would easily stay together in Europe or Japan.

The Silver Lining

There is one major benefit to receiving a restriction requirement called “consonance.”³ If you are forced to split your application into Application A and Application B by the USPTO, the USPTO cannot later use Application A as prior art against Application B during examination, specifically for double patenting purposes. This safe harbor exception under section 121 protects you from being penalized for the very split the Examiner demanded.

Strategy for Applicants

When faced with a restriction, you have three main choices:

• Elect without Traverse: pick one invention and move on.
• Elect with Traverse: pick one, but argue the restriction was improper to preserve your right to appeal later. Talk to your patent counsel to discuss strategy.
• File a Divisional: take the non-elected claims and start a new application to ensure those inventions also get patented. Be sure to file the divisional before the parent issues so you preserve priority rights.

Questions? Please contact Yonaxis I.P. Law Group.

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Footnotes

1. MPEP 802. ↩

2. See also MPEP 1850, MPEP 1893.03(d). ↩

3. MPEP 821. ↩