Very soon all companies in the United Kingdom are going to be producing iXBRL versions of their financial statements and providing those to HMRC (Her Majesty's Revenue and Customs - the tax department). This provides UK companies, especially all listed companies, with a fantastic opportunity to increase the quality of reporting they provide to investors.
As the iXBRL will be required, it seems to me that there would be little additional effort required to make those iXBRL versions of financial statements available on company websites.
One of the benefits of XBRL is the ability to directly consume the information into computer systems to avoid manual re-keying. This is particularly important if a company wants the analyst community to either cover the company, or at a minimum to include the company as a comparator to a covered company. Any need to re-key information would impose time and error costs on analysts, and will 'de-select' that company from the list of comparators, if it is possible to simply import the information provided by another company in the same industry segment.
Therefore, while there is no requirement for companies to post their iXBRL financials on their website (the SEC requires companies providing XBRL to the SEC to also post the XBRL files on their website), to do so is both simple and provides the investor community with additional information, quickly and at almost no additional cost to the company.
What a great opportunity for UK (LSE and AIM) listed companies to get their message out. Don't put the iXBRL in the logical desk drawer, post the iXBRL financial statements on the company website.