Patent status covers things like when was a patent specification published in its different stages, is it awaiting grant, have renewal fees being paid, has it run its full term and expired.
Some patent authorities have made free data available either on separate status databases or have incorporated it in their ordinary databases. The alternative is to ask them. Below is a list of those that I am aware of. Many are in English.
Those that can be accessed via the free Espacenet database are marked by an asterisk *. If a certain record is found, then a link is provided to the status data. For example, see the record for GB2471438, where the link to "GB Register" is just below the Bibliographic data in big, bold type, below the top banner.
I am sorry to say that I gave up trying to find the individual sites for Belgium, Greece and Italy.
European Patent Convention *
Otherwise, Espacenet has an "Inpadoc legal status" tab on the left hand side when viewing information on a patent specification. There is often little data, or it is hard to understand it, but still, better than nothing.
The existence of the legal status databases is not given in the valuable data on Intellogist's Interactive Patent Coverage Map, and I would like to suggest that it would augment an already very useful site. For some reason the French site, at least, is indeed listed and explained. You find data on what online sources (some priced) cover a country by clicking on the continent, then on the country.
It would be helpful if the same software was used by new countries, partly to avoid duplicate effort and partly to help searchers using databases from different patent authorities.
Although I use patent status to determine if a patent is in force, ownership information is also very important for due diligence searches. If a company takeover is contemplated or occurring you obviously want to know what is owned by the company. As companies are not required to record changes in ownership or assignments (to my knowledge it is everywhere voluntary), you cannot rely on the owner name on a published patent specification. There may be false positives (it apparently has patents it doesn't have) or false negatives (it doesn't appear to have patents it does actually have).
Data on litigation (such as links to court cases) is rarely provided, and would again be useful.