ISO plain language standard

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The International Plain Language Federation initiated a project to create a plain language standard through the International Organization for Standardization (ISO). Plain language experts decided to do the standard through ISO for two reasons:

  • the credibility of ISO, which has a network of over 174 national standards bodies and more than 26,000 standards
  • the credibility of being developed with input and support from many plain language experts around the world

A plain language standard provides a clear understanding of what plain language is and how you can achieve it.

Before the standard was published, there were no universally agreed-on principles for creating plain language documents or for determining whether something is plain. This made it difficult for people writing and designing documents to assess the quality of their processes and their documents. Having an international standard means that everyone can now work from the same understanding.

Part 1: Governing principles and guidelines

In 2023, ISO published the plain language standard called ISO 24495-1:2023 Plain language — Part 1: Governing principles and guidelines.

These 4 four principles in the standard give details on what methods you can use to write a plain language document:

  • Readers get what they need (relevant)
  • Readers can easily find what they need (findable)
  • Readers can easily understand what they find (understandable)
  • Readers can easily use the information (usable)

Read the press release

Based on research and consensus

Part 1 of the standard is based on empirical evidence and on the definition of plain language that experts adopted in 2014. In addition, it was created using ISO’s well-regarded consensus model. Experts from 25 countries (representing 19 languages) drafted and approved the standard. Because of all of this work that was done together, plain language practitioners around the world support this standard.

The other parts to the standard were written using the same model.

We’ve published a bibliography of some of the research that the standard is based on.

Works in most languages

The standard is not just for English, nor is it just for ISO’s other two official languages, French and Russian. In fact, the standard is language neutral. So it works in most languages and across all sectors.

50 plain language experts from 25 countries drafted and approved the standard (representing 19 languages). Through the commenting practice used in the ISO consensus model, they were able to make sure every part of the standard works in their languages.

Some countries will localize the standard, to add information that’s specific to a language or to a country. Countries may also develop best practices to reflect what works within their own language, such as sentence length.

More than just words 

The guidance in the standard includes many plain language practices that are not word related. The ISO standard has roughly 485 ideas. These cover a variety of language issues (such as the content’s structure, findability, understandability, and usability) but only 7% focus on word choice. We came to this conclusion by analyzing the words and ideas in the standard.

And the guidance that does relate to words is high level, so it’s not specific to any one language. For example, the standard talks about using culturally relevant language, using words that your readers know, and using clear sentences.

Part 2: Legal communication

ISO published ISO 24495-2:2025 Plain language — Part 2: Legal communication in August 2025.

Part 2 deals with legal communication, and it builds on the foundation for plain language in ISO 24495-1. It establishes guidelines and techniques to help authors make sure that readers can readily understand legal communication and exercise their legal rights and obligations.

It explains how to apply principles from ISO 24495-1 in legal contexts that require authors to achieve these goals:

  • reach multiple audiences with different needs
  • adhere to legally required structural and design requirements
  • explain complex and nuanced legal concepts
  • explain processes that readers must navigate to exercise legal rights and obligations.     

The document applies to legal documents in all sectors, including the legal, governmental, non-governmental and health sectors.

Read the press release in English, French, Italian and Spanish.

 

Part 3: Science writing

ISO published ISO 24495-3:2026 Plain language — Part 3: Science writing in May 2026. 

Part 3 deals with science writing, and it builds on the foundation for plain language in ISO 24495-1.

It focuses on science writing: writing about scientific subjects that is intended for readers with varying education levels, backgrounds and interests. These readers can range from young students to decision-makers in industry and government.

  • This part does not explicitly address scientific writing. Such writing is found in scientific journal articles or academic documents, where experts write for others in their fields of specialization.
  • However, it is possible that other experts do not work in precisely the same field as the author and prefer reading documents that follow plain language guidance.

This document applies to printed or digital information that is primarily in the form of text and images.

Read the press release in English, French, Italian and Spanish. 

 

Notation for business reporting

ISO published ISO 24896:2026 Notation for business reporting in June 2026. This is the first international standard to set consistent design requirements for the visual notation of business reports: charts, tables, and text elements. It was developed to improve the clarity, consistency, and efficiency of business communication worldwide by establishing a common notation for written reports, presentations, and dashboards. 

While not a part of the ISO-24495 series, the work was done by the same working group and builds on the principles of ISO 24495-1.

The initiative was led by the IBCS Association, which maintains the IBCS (International Business Communication Standards) framework.

 

Part 4 and on

ISO is developing a part that will enable an organization to certify that it “uses plain language systematically in its operations.” ISO is also developing more parts to its plain language standard, including document design.  

Implementing the standard

To help you follow the standard and apply it to your documents, the Federation has created some resources, such as testimonials, case studies, and other supporting documents.

Repository of supporting documents

Supporting documents are not published by ISO but they can help you implement the ISO plain language standard, both the general principles in Part 1 and more detailed provisions in other parts. 

Repository of supporting documents

Certification

The current standard is for guidance only and is not for certification. We’ve established a Certification Committee that’s exploring options about this topic.

Testimonials

We’ve collected testimonials from people who are using the standard in real-world situations. If you have a testimonial you’d like us to publish, email it to chair@iplfederation.org.

Case studies

Many people ask for real-world examples that show how plain language works. We’re publishing some plain language case studies from around the world. These outline how various organizations have successfully used the ISO standard as part of a plain language project.

If you have a case study you’d like us to publish, follow the case study guide below and then email it to chair@iplfederation.org.

Case study guide

Our detailed case study guide gives you a straightforward, step-by-step approach to start your plain language initiative.

Creating case studies: a step-by-step guide

Countries can endorse, adopt or sell the standard

A country’s standards body that is a member of ISO can either endorse the standard (just say they agree with the standard as it is), or they can adopt the standard as a national standard for their country.

Some countries choose to just refer to ISO standards rather than endorse or adopt them. Those countries often sell ISO standards that they have not endorsed or adopted.

National standards bodies around the world are translating, localizing and adopting the plain language standard. Within 2 years of its publication, 14 translated it and 21 countries had adopted it or were selling it.

Get involved

If you want to learn more about how your country can adopt the standard, or how to join the team advocating for adopting and using the standard, read these short guidance documents:

You can also join the localization and implementation committee: message us through the contact form at the bottom of this page.

History

Plain language practitioners began formally discussing options for creating an international standard in 2007. Read about how the ISO plain language standard was developed.

Contact us

If you have any questions about the ISO standard, the Federation’s work on the standard, or how the standard can help your organization, please contact us using the form below.

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