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The 2021 ISDA Interest Rate Derivatives Definitions go live – your cheat sheet to the key changes – Lexology

On 4 October 2021, the 2021 ISDA Interest Rate Derivatives Definition (2021 Definitions) succeeded the 2006 ISDA Interest Rate Derivates Definitions (2006 Definitions) as the market standard definitional book for over-the-counter interest rate derivatives transactions. This article considers the key changes between the 2006 Definitions and the 2021 Definitions, the implications of those changes, and their impacts on market participants.

Why were the 2021 Definitions introduced?

The 2006 Definitions relied on the publication of supplements to the initial definitions as a means of updating its provisions over time, resulting in 85 published supplements. Each of those supplements must be read together, along with the original provisions, to accurately interpret the 2006 Definitions; a cumbersome and time-consuming process. The aim of the 2021 Definitions is to consolidate the existing provisions of the 2006 Definitions and related supplements into one publication to overcome these issues.

Can I still use the 2006 Definitions?

The 2021 Definitions were originally published in June 2021 to give market participants time to adopt the new provisions between the publication date and the 4 October 2021 implementation date.

Although the 2006 Definitions will continue to be available for use after 4 October 2021, they will no longer be maintained and updated. Market participants have therefore been encouraged by the International Swaps & Derivatives Association, Inc. (ISDA) to adopt the 2021 Definitions as soon as possible.

Where can I access the 2021 Definitions?

The 2021 Definitions will be accessible on the MyLibrary interface on ISDA’s website (Main Book). When an update or amendment to them is implemented, a new version of the Main Book will be published that automatically incorporates the changes into the existing provisions. On MyLibrary, users will be able to plug in their relevant date and be able to easily access the version applicable to that date.

ISDA has also published an array of resources to assist market participants in understanding the 2021 Definitions. This includes an introduction to the 2021 Definitions, a summary of the key differences between the 2006 Definitions and 2021 Definitions and a video on the implementation of the 2021 Definitions.

What are the key updates to the 2021 Definitions?

Much of what worked well under the 2006 Definitions has been retained in the 2021 Definitions, with major updates limited to the provisions summarised in the table below (capitalised words in the table have the same meaning as in the 2006 Definitions or the 2021 Definitions, as applicable).


The 2021 Definitions are designed to be better structured, more user-friendly and more in line with an increasingly digitised market. If these aims are achieved, the 2021 Definitions will represent a major improvement to the 2006 ISDA Definitions. Whether these aims are in fact achieved will depend on the extent and speed of their adoption by market participants.