XBRL, eXtensible Business Reporting Language, is a standard for exchanging business information. It can be used for financial reporting, and for transferring data between accounting systems. Other are likely to emerge in time.

XBRL, like many other open formats, is based on XML. There are different "taxonomies", additional standards built on XBRL, for different countries and accounting standards, as well as one designed to exchange data between accounting systems (very useful for a company with different systems in different units).

Companies House has developed its own taxonomy, to allow companies to file accounts electronically.

XBRL is an IT standard, not an accounting one. It allows different pieces of software to exchange information. It does not solve the more complex and fundamental problem of the exact meaning of numbers changing with different accounting standards, company choices, and other circumstances.

The above is a common limitation of IT standards: they allow better exchange of information, but not better understanding of it. As an aside, it is worth mentioning that information in databases of company accounts frequently suffers from this problem. A person entering complex data, that is also inconsistent between different companies and countries, into a limited set of database fields has to make simplifying choices. This is made worse by the fact that data entry staff rarely have a deep understanding of accounts.