After the care.data caused uproar with the threat that information about us could be sold to private companies, I'm surprised and shocked that HMRC are doing the same with tax data even if it is anonymised.
No one has given permission for their data to be sold off and the government has no right to do this. I am personally ok with my income and tax payments to be in the public domain but I certainly don't wan't to be part of a data base of information that insurance companies, credit agencies and so on might find useful.
It is one thing for a company to search for my income and tax online, if it were published on a personal website, but it is a completely different matter to allow companies to have that data in a format that allows them to have significant insight into the finances of the majority of people in the country.
The HMRC says that the data will be anonymous but I don't think that is a reason to allow the sale either. There is a reason that the data has value, that reason is to allow targeting of groups of people with increased costs - but also remember that some data can be used to rebuild profiles and detailed information about individuals. If too much identifiable information is stripped out the data loses its value.
There appears to be little public outcry so far, one petition from Change.org and one from the Open Rights Group. Let me know if there are others!