What is a patent, and how do U.S. and international patents differ?
A patent is a government-issued right that gives an inventor exclusive control over making, using, or selling an invention for a limited time, in exchange for publicly disclosing how it works. Patents encourage innovation by protecting new and useful ideas while sharing knowledge with the public.
In the United States, patents are issued by the U.S. Patent and Trademark Office (USPTO) and fall into three main types: utility, design, and plant. A U.S. patent provides protection only within the United States.
There is no single “international patent.” Instead, inventors can file under treaties such as the Patent Cooperation Treaty (PCT) to seek protection in multiple countries through one initial filing. Each participating country (or region, such as the European Patent Office) then examines and grants patents according to its own laws.
What is a USPTO patent publication, and what does it include?
A USPTO publication refers to any patent-related document that has been officially published and made publicly accessible by the United States Patent and Trademark Office.
These publications include both utility and non-utility filings (for example, design or plant) and cover both published applications before grant and patents after grant.
There are two main stages of publication:
- Pre-grant publications (PGPubs): Utility patent applications published before issuance, typically 18 months after their earliest filing date. These disclose pending applications for public review but do not represent enforceable rights.
- Granted patents: Applications that have completed examination and been formally issued by the USPTO. These have unique patent numbers and confer enforceable rights, provided maintenance fees are paid.
Together, these publications form the complete public record of U.S. patent activity and are retrievable by their publication or patent numbers.
See also: What types of U.S. patent documents exist, and how are they numbered? below.
What’s the difference between a pre-grant publication and a granted patent?
- Pre-grant publication (PGPub): A pending utility application made public (usually 18 months after filing). It may still be under examination or later abandoned or continued.
- Granted patent: An examined and approved application with an issued patent number. It represents enforceable rights under U.S. patent law.
Other publication types:
- Design patents (USD) – Protect the ornamental appearance of an article.
- Plant patents (USPP) – Cover new, distinct, asexually reproduced plant varieties.
- Reissue patents (USRE) – Correct, narrow, or broaden a previously granted patent.
- Statutory Invention Registrations (US H-series / SIRs) – A discontinued disclosure-only category (1990–2013) that did not grant enforceable rights.
PatPDFs supports all of these document types. Simply enter a valid number — for example, US 2021/0123456 A1 (pre-grant) or US 9,876,543 B2 (granted).
Why are U.S. applications published after 18 months?
Under 35 U.S.C. § 122(b), most U.S. utility patent applications are published 18 months after their earliest filing date, promoting transparency and public access to emerging inventions.
Design and plant applications are generally not pre-published — design patents appear only at grant, and plant patents are typically published only upon issuance.
Exceptions to the 18-month publication rule include:
- Provisional applications (never published)
- Design and plant filings (publish only at grant)
- Applications with approved non-publication requests
What types of U.S. patent documents exist, and how are they numbered?
U.S. patent documents vary by what they protect (utility, design, plant, etc.). Most non-provisional utility applications publish about 18 months after filing as pre-grant publications. Others—such as design, plant, or reissue—usually first appear when granted or issued.
Each type follows its own numbering and kind-code format:
| Type | Example Number | Description |
|---|---|---|
| Utility Patent Application Publication (Pre-Grant) | US 2020/0123456 A1 | Published utility application, typically 18 months after filing. A1 = first publication; A2 = republication. |
| Utility Patent (Granted) | US 10,123,456 B2 | Issued utility patent. B1 = granted with no prior publication; B2 = granted following a pre-grant publication. |
| Design Patent | US D901,234 S1 | Protects ornamental design. |
| Plant Patent | US PP12,345 P2 | Protects new plant varieties. |
| Reissue Patent | US RE45,678 E1 | Reissued to correct or modify an earlier patent (for example, to fix errors or adjust claim scope). |
| Reexamination Certificate | US 6,368,227 C1 | Issued after re-examining an existing patent; modifies but does not replace the original grant. |
| Statutory Invention Registration (SIR) | US H1,234 H1 | Discontinued USPTO publication type disclosing an invention without enforceable rights (supported for archival reference). |
Formatting tips:
- Kind codes (A1, B2, etc.) identify the document’s status.
- U.S. application publications include the year and a slash (e.g., 2019/0123456).
- Granted patents use sequential numbers (e.g., 10,123,456).
How should I enter numbers in PatPDFs?
PatPDFs recognizes all standard U.S. patent and publication numbering formats.
Enter:
- a published application like
2017/0123456or2017/0123456 A1, or
- a granted patent like
10,123,456orUS10123456.
Tips:
- Punctuation and spacing are flexible; PatPDFs normalizes formats automatically.
- The US prefix and kind code (A1, B2, etc.) are optional.
- PatPDFs intelligently infers missing elements.
Are there patent types PatPDFs does not support?
- Provisional applications (e.g.,
63/123,456): These establish an early filing date but are not examined or published. Because they have no public document number, PatPDFs cannot retrieve them. Use the corresponding non-provisional publication or patent number instead.
- Non-U.S. patents (e.g., EP, WO): Currently not supported.
What’s the difference between a publication number and an application number?
- Application number (App No.): Assigned when an application is first filed (e.g.,
17/123,456). It refers to an internal USPTO file and may not correspond to a public document. - Publication number (Pub No.): Assigned when a patent application is published or when a patent is granted (e.g.,
US 2023/0123456 A1orUS 10,123,456 B2). It identifies a specific, publicly available document.
PatPDFs retrieves published documents only, so it uses publication and patent numbers, not application numbers.
To search by application number, use Patent Toolkit or the USPTO Patent Public Search (PPUBS) portal.
Kind codes — what they mean & why they matter
| Code | Meaning |
|---|---|
| A1 | First publication of a utility patent application |
| A2 | Republication of a utility application |
| B1 | Granted utility patent without prior publication |
| B2 | Granted utility patent with prior publication |
| C1 | Reexamination certificate — issued after the USPTO re-examines an existing patent; updates or confirms the original grant |
| S1 | Design patent |
| P2 | Plant patent |
| E1 | Reissue patent |
| H1 | Statutory Invention Registration (SIR) |
Kind codes help identify the document’s type and publication status at a glance.
What is OCR, and why does PatPDFs support it?
OCR (Optical Character Recognition) converts scanned images of documents into searchable, selectable text.
PatPDFs supports OCR as an optional feature that runs before the PDF is delivered. It may take slightly longer but produces a searchable file ideal for analysis or archiving.
Benefits:
- Full-text search within documents
- Copyable, selectable content
- Improved accessibility (screen readers, assistive tools)
- Enhanced keyword indexing
For fastest downloads, leave OCR disabled; when you need searchable text, enable OCR for that request.
What data sources does PatPDFs use?
PatPDFs retrieves documents from two trusted sources for accuracy and reliability:
- PatPDF Archives – The primary, fastest-access cache maintained by Patent Toolkit. It stores documents directly sourced from the USPTO for quick retrieval.
- USPTO PPUBs – The official USPTO publication service for both pre-grant and granted documents, used when a file isn’t yet cached.
This dual-source approach ensures high availability and authentic documents every time.
What are continuation or divisional applications, and how do they relate to what I see in PatPDFs?
A continuing application is a follow-on filing (made while an earlier non-provisional is pending) that claims benefit of the parent’s filing date.
- Continuation (CON): Same disclosure, new claims.
- Divisional (DIV): Split from a restriction requirement.
- Continuation-in-Part (CIP): Adds new subject matter (new disclosure has a new priority date).
In PatPDFs:
Each continuing application, once published or issued, has its own publication or patent number and is retrievable separately. Continuations and divisionals may share the parent’s priority date but have distinct document numbers.
Continuing applications apply only to non-provisionals; they cannot claim from a provisional.
Tip: When tracking a parent application, monitor the family for later-published continuations or divisionals — each will appear separately in PatPDFs.