An audit tells you the state of accessibility of your service. The audit results will make it easier to plan the development of the service with accessibility in mind.
There is no obligation to have an accessibility audit, i.e. it is not required by law. However, an accessibility audit is often the easiest way to determine the overall accessibility status of a service.
An accessibility expert usually has a good and comprehensive understanding of accessibility. The understanding includes the WCAG requirements as well as accessibility as a whole. They also tend to follow accessibility discussions and receive continuous training. Experts are usually also aware of future requirements. Auditing is more efficient when all this knowledge is available to the author.
The Act on the Provision of Digital Services defines accessibility requirements in Finland. The Act implements the European Union Accessibility Directive (EU 2016/2102) and, from 28 June 2025, the European Accessibility Act (EU 2019/882).
The accessibility statement should always have an up-to-date status of accessibility. One part of the accessibility requirements is to provide an accessibility statement of the service.
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Just because a service was created to be accessible and tested to be accessible does not mean that the service will remain accessible. Content providers, developers and designers alike sometimes make mistakes. And these mistakes can lead to an accessibility error.
Technology and standards are also constantly evolving. Tools, browsers and operating systems get new features all the time. The new features may exist in only some of these at the same time. Similarly, features may be deprecated at different times. This can also sometimes lead to errors.
Currently, the accessibility requirement is for WCAG 2.1. WCAG 2.2 was released in October 2023. This version will at some point become part of the requirements of the law. After that, there is no guarantee that a previously accessible site will remain so.
An accessibility audit is not a one-off exercise. If the service is never upgraded, then it can be argued that there is no need for an annual audit. But usually, services are updated more actively, so audits should also be done once a year, for example. Even if the service is also subject to continuous accessibility monitoring, it would also be good to carry out an audit regularly.
There are no requirements for the frequency of accessibility audits. A general recommendation is about once a year. Some recommend audits up to four times a year.