International · Reference
Patent kind code lookup.
Find out what the letters at the end of a patent number mean. Type a code such as B2, or a full number such as US 10,123,456 B2, and get the plain meaning from the USPTO tables and WIPO Standard ST.16.
Short answer: on a US number, A1 is a published application, B1 is a granted patent with no earlier publication, and B2 is a granted patent that was published earlier as an application. S is a design patent and E is a reissue. Other offices use the generic WIPO ST.16 letters.
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Enter a kind code or a number and press Look up.
How to read a patent number
WIPO Standard ST.16 recommends identifying a patent document by its two-letter office code, its number and a kind code. The USPTO gives the same advice: for example “US 7,654,321 B1” for a granted patent with no earlier publication, and “US 2003/1234567 A1” for an application publication. Application publication numbers restart each year, so they carry the four-digit year.
| Code | Kind of document | Comment |
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| Code | Kind of document | Comment |
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| Letter | Group | Meaning |
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The digit: under ST.16, a digit after the letter refines it. Each office decides what digits 1 to 7 mean. The recommended uses are 8 for a correction that reprints the first page and 9 for a correction that reprints part or all of the document; 0 is used by some offices internally.
Not covered
The two source documents give office-specific meanings only for the United States. What EP, WO, CA or GB print under a given code is set out in ST.16 Part 7.3.2, so those offices show the generic ST.16 meaning here and nothing more. Numbers with letter prefixes (such as reissue or design numbers) are not parsed.
Reference lookup only
This page explains kind codes. It does not check that a patent number exists, was granted, or is in force; use the issuing office's own database for that.
Sources
- USPTO, “Kind Codes” Included on the USPTO Patent Documents (US codes and comments)
- WIPO Standard ST.16 (letter groups and digit rules)
Privacy and scope
This tool runs entirely in your browser: nothing you type is transmitted, stored, or logged. It is a reference for what codes mean, not legal advice and not a patent search.