Disclaimer
The information in this section should not be taken for legal advice and is intended to be used for information purposes only. The examples provided are not intended to be recommendations, nor is the NDA in the position to provide legally verifiable pathways to comply with the European Accessibility Act.
Definition of accessibility
"Accessibility is defined as the extent to which products, systems, services, environments, and facilities can be used by people from a population with the widest range of user needs, characteristics, and capabilities to achieve identified goals in identified contexts of use."
-Source, ISO 9241-112:2025, 3.11
Put simply, accessibility means the extent to which products and services can be used by many different people, with different user accessibility needs, in a variety of situations.
What does it mean to be able to use a product?
Using a product or service involves three things:
- Accessing it
- Understanding it
- Using it effectively
If one or more of the above is missing, the product or service is not fully accessible.
To be accessible, a diverse range of users need to be able to access, understand, and use a product or service.
Example: Ticket machine at a bus station
Consider you are developing a self-service ticketing terminal to be used at a bus station. To make that product accessible you will need to consider the needs of a diverse range of users:
- How might a wheelchair user access the terminal?
If the buttons of the terminal are positioned too high, a wheelchair user might not be able to access it. Lower positioning might help them better access the terminal. - How might a person with an intellectual disability better understand how to use the terminal? Technical usage instructions might not be adequate for a person with an intellectual disability. Plain language instructions or explanatory images might help them better understand how to use the terminal.
- How might a person with a visual impairment use the device? If only a touch screen is provided a visually impaired user might be restricted in their use of the terminal. Including alternative modes of interaction would increase the usability of the terminal.
Understanding different users
Everyone has different characteristics, capabilities and needs. Designs should work for as many people as possible.
What are characteristics?
Characteristics are traits people are either born with or develop over time. Examples include body size or skin colour. Neither of these characteristics suggests how a user may function, but they could have bearing on design.
Examples:
- A very tall person may need to adjust a product so that it can be used at their eye level.
- Someone with small hands might need a product to be smaller to hold it comfortably.
- People of different skin colours can experience different UV sensitivity which is an important consideration in the design of some products.
What are capabilities?
Capabilities are the actions people can perform at a point in time. Everyone has a different set of capabilities. For most people capabilities change substantially throughout the course of their life, as they advance from childhood to adulthood and then into old age. The functionality of a product or service is dependent on how well a user’s capabilities are considered in its design.
Example: Photosensitive epilepsy part one
An individual’s susceptibility to photosensitive seizures might fluctuate with treatment. Seizures might also result in changes in their physical capabilities.
What are needs?
Specific needs related to accessibility are known as user accessibility needs, which the International Organization for Standardisation (ISO)/International Electrotechnical Commission (IEC) define as "user need related to features or attributes that are necessary for a system to be accessible."
Needs are the requirements people have of a product or service. Often these requirements are related to a person’s characteristics and capabilities.
Example: Photosensitive epilepsy part two
Having a product that can be:
- adjusted to limit flashing lights or fast-moving visuals, and
- can be used with limited range of motion
could help meet the requirements of a user with photosensitive epilepsy as their user accessibility needs fluctuate.
Design for the widest range of users
The widest range of users is a concept that calls for products and services to be designed with consideration for the greatest possible range of human diversity. This means taking into account as many different needs, characteristics, and capabilities, as possible.
To understand, and eventually meet, the widest range of users’ needs you must involve a diverse set of potential users of your products and services.
Universal Design
Universal Design is a concept that aims to design for all users. Universal Design prioritises accessibility by involving the widest range of users in the design and development process. There are 7 principles of Universal Design, each with their own set of design guidelines. Applying the principles and following the guidelines will help you optimise for accessibility in your designs.
Testing for accessibility
For further insight into user characteristics and why it is important to consider them in your designs, check out our Testing Primer. To access the Testing Primer go to our Guidelines on Body Size web page and look for "Testing" in the list of linked documents.
Learn about best practices for user testing for digital content in web accessibility techniques guidance.
What are ‘identified goals in identified contexts of use’?
An identified goal is the outcome the user would like to achieve by using a product or service. An identified context of use is a specific situation in which the user will use the product or service. Identified contexts can include the time and place of use, as well as circumstances particular to the user and their environment.
Example: Using a watch in water
- The identified goal of a watch is to allow the user to read the time.
- The identified context of use of a particular watch might be during day-to-day activity but not including sports or in wet conditions.
- The watch in this example has not been made for use in wet conditions. Therefore, it is outside of the product’s context of use to be used in heavy rain, or while swimming. This would not make the product inaccessible, as these circumstances are outside its context of use.
Context and accessibility
Context of use refers to the specific circumstances and setting in which a product or service is used. The context of use of a product or service is often linked to the characteristics, capabilities and needs of the user. Therefore, context of use often impacts how accessible a product or service is.
Example: Paying with a screen reader in public
In a scenario where a person with a visual impairment needs to make a payment on their phone in a public place, they might use a screen reader. For privacy purposes, they might use earphones and dim their screen. In this context of use, they are able to privately make the payment while still in public.
Maximising foreseeable use
For every product or service, there is a range of uses. These uses may be intended from the outset, but unintended uses can also emerge as a product or service moves through its lifecycle. A foreseeable use is how we might reasonably expect people to use a product or service. Maximising foreseeable use means anticipating the widest possible range of uses that a product or service might experience in the future—including those we might not have intended.
The EAA requires maximised foreseeable use
The European Accessibility Act says that products and services must be designed so that they maximise foreseeable use by people with disabilities. This includes uses with assistive technology (AT). Therefore, design should support all realistic, expected uses by people with disabilities. This is a requirement under the EAA.
Accessibility is layered
Accessibility is layered, meaning that several aspects of the environment interact and influence the degree of accessibility experienced by any one person.
Example:
Consider a self-service ticketing machine that has the capability to read out the text it displays for blind users. However, the self-service ticketing machine is placed in a loud, busy environment without the capability to support headphones making it impossible to use for blind users in peak commuting times.