Did you know … how to perform a search in Espacenet by numbers

Why it can be difficult to find a patent document by searching by a number - and how to overcome this challenge

• Typographical errors: Simple mistakes in entering the number.
• Database coverage: The corresponding patent document may not (yet) be included in the Espacenet database.
• Format discrepancies: If the number does not conform to the standard Espacenet DOCDB format, it often leads to unsuccessful searches.

Espacenet standard number format

The standard Espacenet number format is:
CC(ccyy)n(nnnnnn)KC — with no spaces.

Here's how to break it down:

• CC: Country Code
• cc: Century
• yy: Year
• n(nnnnnn): Serial number of variable length
• KC: Kind Code (for publication numbers only)

In the following example “JP2021511705A”, JP is the country code, 20 the century, 21 the year, 1511705 is a 7-digit serial number and A is the kind code.

Note: The century, year and the number of digits in the serial number in brackets may vary in the patent numbers depending on the country, the time period and kind code.

Tools and resources for accurate searches

To help identify the correct number format, the EPO provides a useful resource: the “Publication, application, priority numbers concordance table” (see links under “Further information”). This document outlines the formats used by various patent authorities, helping ensure that search queries align with Espacenet’s DOCDB conventions.

Fig.1: Publication, application, priority numbers concordance table

Coverage in Espacenet

It is important to note that NOT all numbers/documents are available in Espacenet. To better understand the scope of data coverage, we encourage you to consult the "Contents and coverage of the DOCDB bibliographic file) (see “Further information” below).

Searching by number is straightforward when the number conforms to the standard format, such as AT526459A2 (note that spaces should be removed).

However, this is not always the case. For instance, searching for a US-granted patent, by a number like US 10,896,908 B2 or even US10,896,908B2 (without spaces), will return no results. To retrieve the document, the number must be entered in the standard Espacenet format: US10896908B2.

Some patent authorities use formats that differ significantly from the standard Espacenet format. For example:

• The Japanese original publication number P2021-511705A is formatted as JP2021511705A in Espacenet.
• The Korean original publication number 86-4478 (U) is formatted as KR860004478U (publication of utility model application)

Espacenet displays the standardised number format in both the result list and the document pane.

Fig. 2: Number format to search for KR860004478U

Moreover, for PCT publications, both the standard format (WO2022155014A2) and variations (WO2022/155014A2 or WO 2022/155014 A2) can be used effectively in Smart Search, enhancing the flexibility and success of your searches.

Search for more than one patent document by number

If you want to search for more than one patent document at a time, the easiest method is to use Advanced search and enter the numbers of all desired documents in the respective number field.

For example, you could input in the Publication number field:
US10896474B2 EP3621049B1 CN111186442B

Ensure that the any operator is selected — this functions like a Boolean OR between the search terms.

Fig. 3: Search by more than one number

The equivalent Smart search query would be:
pn any "US10896474B2 EP3621049B1 CN111186442B"

In 2023, Espacenet expanded the maximum number of search terms from 20 to 500, within the browser’s URL length limit. This expansion allows for more comprehensive batch searches in a single query.

For further information, feel free to watch our Patent Knowledge Nuggets video on YouTube and visit our dedicated help page using the links below.