British patent numbers 1916 - 1981

Since the start of 1916 published patent specifications (for patent applications filed before 1 July 1978*) have been numbered in a series starting at 100001 in January 1916, separate from patent application numbers. Although the majority of patent applications filed before 1 July 1978 had been granted and published by the early 1980s, a small number continue to be published today. The present serial number is somewhat over 1605000; there are no British patent numbers between 1610000 and 2000000.

*Patent applications filed after 1 July 1978 are published with seven figure serial numbers beginning with "2".

Note: After 1916 generally only granted patents were published; those not granted were never published and no information on them is now available. However following the introduction of the Patents & Designs Act 1907 (Section 91(4)), patent applications originating abroad and which claimed priority were laid open for public inspection after 12 months (later, 18 months), if not granted by then; many of the patent applications laid open were also printed and given numbers in the six-figure series - these are available. The practice of printing these foreign applications ceased during World War II, and was abolished under the Patents Act 1949.

If you write to the UK-Intellectual Property Office in connection with any British patent number, please precede the number with the letters "GB" to make it clear that a British patent is being referred to - similar serial numbers appear on the patents of many countries.

The following table shows the lowest patent number for specifications published in each calendar year.