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New biological sequence listings requirements for patent applications

From 1 July 2022 a new global standard will apply to all new patent applications containing biological sequence listings. The new standard is known as WIPO ST.26 and applies to biological sequences with ten or more defined nucleotides or with four or more defined amino acids. This change is being adopted by all WIPO contracting states including the European Patent Office (EPO) and the UK Intellectual Property Office (UKIPO).

Details of WIPO ST.26 are available here. In addition, new software, WIPO Sequence, is available to download for applicants to compile sequence listings under the new standard. Importantly, the sequence listing must be in XML format and not TXT format.

The EPO sets out its practice on the filing of sequence listings from 1 July 2022 here. Similarly, the UKIPO has published new requirements and procedures in the document Changes for patent applications with biological sequence listings.

Importantly, both offices require that where a divisional application is filed after 1 July 2022, any sequence listing must comply with the new standard. Thus, if the sequence listing in the parent application was prepared under the old WIPO ST.25 standard, it will need to be updated to the new standard and filed in the divisional application with a statement that it does not add subject matter.

For PCT applications filed before 1 July 2022, the old ST.25 standard will continue to apply, even if the application enters the EP regional phase or GB national phase after this date.


If you have any questions on this topic, please contact Andy Cloughley at

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