Conducting a patent search before filing a patent application is recommended.

Conducting a patent search will allow tailoring of a subsequent patent application in view of the documents raised by the search.  The documents raised by the search are likely to be cited during examination of the patent application.

Search Limitations

The search strategy of a patent search may involve keywords, alternate expressions and patent classes. Given various possible patent search strategies, no patent search can be considered fully conclusive.

Additionally, patents are generally not published until 18 months after filing.  For this reason, a patent search will not cover applications filed at least 18 months prior to the search.

A literature search is sometimes conducted as part of a patent search.  Searching of literature databases is limited to the literature search strategy.

Cursory Searches

If a cursory patent search is performed, at least the US database and European database (Espacenet) should be searched using the links provided below. The Internet should also be searched to determine whether similar products already exist in the market.

In addition to Espacenet, the European Patent Register has advanced searching capabilities.

For example, it is possible to search by grant date.

Search: (grd=2016 grd=2017 or grd=2018) and  ((pa=facebook or pa=ebay) or ti=social)


It is also possible to search the Australian Patent Office database (AUSPAT) for say recently granted software patents.  Search terms could include ‘computer’ and ‘responsive’.  The wildcard ‘*’ can be used as a truncation operator when limiting by IPC class.


A picture containing text, screenshot, monitor, indoor  Description automatically generated

Google and Espacenet offer similar functionality.  For example:


AUSPAT can be used to obtain file wrappers.


A professional search firm in Australia may charge between A$3,500-$6,000++ or more for a standard comprehensive search (no literature searching).  We charge approximately $500 for preparing a search statement and instructing a professional search firm. A cursory search may cost about $1,500.

If you would like us to assist in reviewing the search results, further charges will apply.

A number of Australian search firms are detailed below.

Patent Classification Searching

It is possible to do some class based searching of publicly accessible databases such as Espacenet.

University library websites such as the University of Bath website often provide an excellent basic guide to patent searching.  A number of videos on searching using various classification systems are provided below. 

The field, structure, function and use of the invention each provide relevant keywords.  A structural thesaurus and a functional thesaurus (indexes) are generally compiled as part of a search (together with classes).  Indexes are important given the possibility of alternative keywords.  For example, consider ‘electronic cigarette’ versus ‘simulated cigarette’ versus ‘inhaler’.  A patent searcher will generally apply several searching techniques (See for example https://www.acclaimip.com/how-to-do-a-patent-keyword-search/). 

CPC classification of a European patent is shown below.




 A24F7/00 Mouthpieces for pipes; Mouthpieces for cigar or cigarette holders

 A24F40/485 Valves; Apertures

 A61M15/06 Inhaling appliances shaped like cigars, cigarettes or pipes

 H01C17/00 Apparatus or processes specially adapted for manufacturing resistors

 H05B1/0244 Heating of fluids

 H05B3/0014 Devices wherein the heating current flows through particular resistances

 H05B3/10 Heater elements characterised by the composition or nature of the materials or by the arrangement of the conductor

 A24F40/10 Devices using liquid inhalable precursors

 A24F40/40 Constructional details, e.g. connection of cartridges and battery parts

 A24F40/44 Wicks

 A61M11/001 Particle size control

 A61M11/04 Sprayers or atomisers specially adapted for therapeutic purposes operated by the vapour pressure of the liquid to be sprayed or atomised



CPC Classification

The European Patent Office (EPO) and US Patent Office (USPTO) now both use the CPC classification system.  CPC classes provide a further particularisation of IPC classes.  It is possible to do a conversion from CPC to IPC.  For example CPC class  G06F 16/3343 {using phonetics} (four dots) ‘ is a further particularisation of IPC class G06F 16/33 Querying (two dots) as detailed on https://www.uspto.gov/web/patents/classification/cpc/html/conG06Ftoipc.html#G06F16/3349.

The EPO provides a number of learning resources online including https://e-courses.epo.org/course/index.php.  General search strategy is also covered.

Graphical user interface, application  Description automatically generated


Where to start

There are a number options as to where to start.

One option is to start with the Catchword Index or IPCCAT.  In this regard: With the new cross lingual IPCCAT-neural, system for automatic text categorization in the IPC, it is possible to perform automatic classification in the IPC at subgroup level through submission of text which can now be either in Arabic, Chinese, English, French, German, Japanese, Korean, Portuguese, Russian or Spanish, and get an accuracy of the predictions similar to the one in English, i.e. 84% for top-three IPC guesses among 73,633 symbols. (WIPO)

A search for ‘electronic cigarette’ using IPCCAT provides a good example.  IPCCAT returns: ‘A24F 47/00; A61M 15/06; A61M 11/04‘ as a prediction.

Usually, however, it is still necessary to directly search class headings online.  Keyword searching to locate relevant patents and associated inventors to determine further classes is also advisable.

The EPO provides a classification search guide.

A search of the CPC classification system using Espacenet yields the following results. 

Graphical user interface, text, application  Description automatically generated


Various class mappers are listed on the EPO website.  The USPTO database supports searches using the US Patent Classification (USPC) for US patents from 1790 to the end of 2014. The US classification then switched to CPC classification. The USPTO provides: (i) Classification search; and (ii) USPC and CPC tools. 

Tools such as DTSearch and other indexers can be used on CPC pdf/xml documents for overview purposes.