“… are regulated by Department for Education (DfE). It’s worth noting that all three regulatory bodies [the Charity Commission, Office of the Scottish Charity Regulator and DfE] are subject to the Freedom of Information act, which means that you may be able to uncover information about a charity’s compliance with the Charities Act 2006.
“Regardless of whether or not the organisation you are investigating is registered as a charity, it is worth searching the records at Companies House to find further information.”
More tips on the original blog post. Can you add any?