Similar in Portugal (Score 3, Interesting)

In Portugal, for the last couple of years it is already required for every business to have a "certified" software that enforce some similar rules. Even though the software doesn't need to be open source, every invoice or receipt must include part of an hash key that is automatically generated based on key data (VAT Nr, amount, date, value), an asymmetric key given to each software manufacturer *and* the hash from the previous document. This makes it impossible to change any document after it has been printed out without invalidating every document printed after it. There was a requirement that every software had to be able to export accounting details in a standard format (SAF-T), if requested from the tax authority. Since 1-Jan-2013 every business is now forced to send monthly detailed invoce data to the tax authority.