Restriction requirement
A US patent examiner's notice that an application claims more than one distinct invention, forcing the applicant to elect one group of claims for examination.
A restriction requirement is a procedural action by a USPTO examiner when a single patent application appears to claim more than one distinct invention. The applicant must elect one group of claims for examination in that application; the non-elected inventions can be pursued separately, typically through divisional applications.
Where it applies: Restriction requirements are a feature of US (USPTO) practice. Many other jurisdictions — including the European Patent Office — apply a related but differently shaped doctrine called unity of invention, which can produce comparable outcomes (divisional applications, additional fees) under different rules.
Consequences for the portfolio: A restriction requirement does not destroy claims; it splits them across filings. That has cost and timing impact: each divisional carries its own filing, examination, and renewal fees, plus extra prosecution work. The upside is that divisionals inherit the parent's priority date, so the family's effective scope can still be preserved — provided the divisionals are filed within the deadlines. IP managers should plan budget and deadlines for likely divisionals up front, and consider drafting strategies that minimise the chance of an unwanted restriction.