The new site aims to conform to level AAA of the W3C Web Accessibility Initiative guidelines, the standards regarded by governments and usability professionals as key in assessing site accessibility.
People using screen readers (devices that read the content of a web page aloud) to access the site can now access the content immediately.
Download times have been improved, Webcredible claims. An automated 'print friendly' feature has been added, which formats copy and removes images when a user prints a page.
"We're delighted with the new site. It is essential that everyone can access it," says Daryl Barrett, external relations manager of Postwatch. "Not only does the site aim to conform to the highest standards of accessibility, it is also designed in a way that reflects our brand image."
A non-profit organisation, Postwatch is hoping the site will encourage other organisations to improve the accessibility of their sites. It follows a study unveiled by the Disability Rights Commission in May, which reported that 80 per cent of 1,000 UK sites tested failed.