This page deals with how to search for old British patents using free online sources and by visiting the British Library
At present not all British patents are available online. The Intellectual Property Office is in the process of digitising historical British patents and having them loaded onto the European Patent Office's Espacenet® database, but so far this has been achieved only as far back as 1890.
Before you start searching, note that patents cover technological innovations, not specific products. There may well not be a single patent "for" some product, machine or vehicle that you own, and patents do not usually contain brand names or model names for the products they apply to. Rather, there may be a patent or patents for specific and sometimes very narrow technical aspects of a product, especially if it is a complex machine or vehicle. Also, patents describe technical innovations in general terms and the illustrations will only be detailed and accurate enough to properly represent the innovation. Illustrations will not contain measurements, may not show the whole of a complex product, and may not even show the innovation they describe in the precise form that it existed in real products. Therefore, you may well be disappointed if you are looking for the type of detailed technical drawings required to restore or replicate an antique.
Searching for old British patents on Espacenet®
British patents published after 1890 can be searched on Espacenet® by their number, title, words in the abstract (brief description), applicant name, or by the Co-Operative Patent Classification (CPC). We have produced a general guide to searching Espacenet®, but there are some special issues when searching for older British patents on it.
- Because Espacenet® contains patents from many countries, if you want to search by number you need to put GB before the number with no spaces, such as GB574832. This two-letter code is called the "country code" and indicates the country where the patent was published. (A complete list of them is published by the World Intellectual Property Organisation)
- Before 1916 British patent numbers returned to one at the beginning of each year. The number format used for them on Espacenet® is GByyyynnnnn where yyyy is the full four-digit year and nnnnn is the five-digit number. If the number has less than five digits you need to add zeroes at the beginning to make it five digits, so that for instance patent number 154 of 1905 is recorded on Espacenet® as GB190500154. In 1916 a continuous number series began, starting with GB100001. If you have a patent number with five digits or less and no year is given there is unfortunately no easy way on Espacenet to retrieve all patents with that number. You will have to try searching by applicant and/or subject, or if you have the patience try each year in turn in the format above. Although it is less common, it is also possible that a number with five digits or less may refer to a British application number, assigned from 1916 on to patent applications in their early pre-publication stages and also numbered starting with one at the beginning of each year. These are often searchable on Espacenet® in the same format as above in the "application number" field, but again they are extremely difficult to trace if the year is not given.
- Although most of the old British patent records on Espacenet® have detailed searchable records of applicants and titles, there are some spelling errors in applicant names and a few records have missing titles or applicants. If you are searching by applicant name then to be absolutely exhaustive you should also check the paper indexes in the British Library.
- It was only after the Patents Act 1977 that inventors who were not also patent applicants were required to be formally credited as such, so searching in the "Inventor" field on Espacenet® for personal names may give very variable results before that date and they may not be recorded at all. If searching for a person's name you should always try both the "Applicant" and "Inventor" search field as separate searches - do not try to use both boxes at the same time as this will only find results with the name in both places.
- From 1884 to 1915 British patent numbers were assigned very early in the application process. Many were never published because the application was rejected or the applicant gave up early on. If the application was never published the number will not retrieve anything on Espacenet® and there will be no explicit statement that the application was abandoned: the search will simply not retrieve anything. The same thing will occur if you have a post-1916 application number and the application was abandoned early on. The only record of unpublished applications is the very brief announcement in the Official Journal, which is not online prior to 1998. We have copies on paper, but the announcements can only be retrieved easily by known number before 1915, or applicant name and date after 1916. The only information in them is the applicant's name and contact address (which is often a legal representative's rather than their own), and a very brief title for the invention. They were not published at all for much of World War II, due to a combination of paper shortages and heightened technical secrecy.
Is your number a British patent number?
If you cannot find anything, it may also be because the number you have is not a British patent number. British patent number markings on objects usually contain the word "patent" or abbreviation "pat." somewhere. A "registered", or "reg." number in the UK usually refers to a trade mark or registered design. Most records on old UK registered designs are held by the National Archives, who also have a specific web page on the subject. Old UK trade marks are, unfortunately, very difficult to retrieve information on by number.
Sometimes the patent number on the item may not relate to the UK.
- Objects subject to French patents are generally marked with "brevet" or "brev." numbers, and from roughly World War I onwards the documents can be retrieved by number on Espacenet® using the country code "FR" at the beginning. French patents from the eighteenth and nineteenth centuries can be searched for on the French National Institute of Intellectual Property web site. This database is only available in French: in the "Recherche avancée" "mot du titre" means "word in title" and "Déposant" refers to the applicant name.
- Objects subject to German patents from the nineteenth or early twentieth century are often marked with numbers beginning "DRP", which allow you to find the document on Espacenet® by searching with the number using a "DE" country code. German objects may also be marked with DRGM numbers, which refer to "Gebrauchsmuster", a type of German intellectual property for minor inventions with no direct British equivalent. You may be able to find details of them on the German national database Depatisnet, using DE as the country code and a "U" after the number to indicate that it is a Gebrauchsmuster rather than a patent.
- Objects subject to US patents in the nineteenth and early twentieth century were usually marked with the date the patent was granted rather the number. Unfortunately you cannot easily search using this information online, but please contact us for further details.
A simple number printed or engraved on an item may, however, not be a patent number at all, but some kind of model number or catalogue reference, or a part, batch or serial number. There is no general record source for these and it may well not be possible to find out what they mean unless the manufacturer's records survive somewhere. It is often not possible to get any information from these unless you have already identified the manufacturer.
Searching for very old British patents using paper indexes
If you are looking for a patent from before 1890 there is no online search available and you need to use the paper indexes published by the Patent Office at the time. Relatively few copies of these survive. We have a complete set, and a few other libraries with patent collections worldwide also do. The PATLIB UK network comprises British libraries with patent collections, but not all have historic material available. If you live near one, we suggest that you check with them by phone or email before you visit.
You can see full details of the paper records we hold at the British Library on our Great Britain documentation page. However, the most useful sources are:
- Indexes by applicant name in alphabetical order: there is one volume covering the period from 1612 to 1852, and after that roughly one volume per year.
- Collections of abridgements (brief abstracts) of patents on specific technical areas: the period prior to the beginning of Espacenet® coverage is covered by two different sets. One covers the period 1855-1930 and includes all patents. The other covers the period from the seventeenth century to the 1860s-80s depending on the technical area, and unfortunately does not cover all areas (for example, glass and cutlery were not included). Each volume of both sets of abridgements contains more detailed subject indexes, and applicant name indexes, for patents on the subject.
We can do a brief search for you if you contact us, which can cover a single person's name for all subjects over a ten-year period. If you want to restrict it to a specific subject we may be able to perform an applicant name search over a longer period depending on whether the subject falls within a single abridgement volume. We may also be able to check a number for you if you know the year or the exact subject.
If you want to do any more extensive searching, such as a general search for patents on a technical subject, you will have to visit the Library or pay our Research Service to do the search for you. Please check the proof of identity that you will need to bring with you, and our opening hours, before you come.
If you have any further queries about patent searching, please ask us using our contact form.