Chat Sketches with the Companies House API, Before the F***kWit UKGov Sell It Off

Ranty title a gut reaction response to news that the Land Registry faces privatisation.

Sketching around similar ideas to my Slack/slash conversational autoresponder around the Parliament data platform API, I thought I’d have a quick play with the UK Companies House API, which provides a simple interface to company registration data, director information and disqualified director information.

Bulk downloads are available for company registration information (here’s a quick howto about working with it; I’ll post a howto showing how to work with it using a containerised database when I get a chance, but for now, here are some clues) and from the API developer forums it looks as if bulk director’s information is available by request.

Working with your own bulk copy of the data is preferable, because it means you can write your own arbitrarily complex queries over any or all of the columns. The Companies House API, on the other hand, gives you a weak search over company and directors names, and the ability to look up individual known records. To do any sort of processing, you need to grab a large amount of search data, and/or make lots of individual known item records to build you own local datastore, and then search or filter across that.

So for example, here’s the first fumblings of my own function for filtering down on a list of officers associated with a particular company based on director role or current status (which I called typ for some reason? Bah:-(:

def ch_getCompanyOfficers(cn,typ='all',role='all'):
    #typ: all, current, previous
    if typ=='current':
        co['items']=[i for i in co['items'] if 'resigned_on' not in i]
        #should possibly check here that len(co['items'])==co['active_count'] ?
    elif typ=='previous':
        co['items']=[i for i in co['items'] if 'resigned_on' in i]
    if role!='all':
        co['items']=[i for i in co['items'] if role==i['officer_role']]
    return co

The next function runs a search over officers by name, but then also lets you filter down the responses to show just those directors who also match a particular search string as part of any company name they are associated with.

def ch_searchOfficers(q,n=50,start_index='',company=''):
    url= ''
    if company != '':
        for p in o['items']:
            p['items'] = [i for i in ch_getAppointments(p['links']['self'])['items'] if company.lower() in i['appointed_to']['company_name'].lower()]
        o['items'] = [i for i in o['items'] if len(i['items'])]
    return o

You get the gist, hopefully. Run a crude API call, and then filter down the result according to particular data properties contained within the search result.

Anyway, as far as the chatting goes, here’s what I’ve started playing around with…

First, let’s just ask what companies a director with a particular name is associated with.


We can take this a bit further by filtering down on the directors associated with a particular company. (Actually, this is simplified now to call the reporting function simply as dirCompanies(c)).


Alternatively, we might try to narrow the search for directors associated with companies in a particular locality. (I’m still trying to get my head round the different logics of this, because companies as well as directors are associated with addresses. I really need to try some specific investigative tasks to get a better feel for how to tune this sort of filter…)


I’ve also started trying to think around the currency of appointments, for example supporting the ability to filter down based on resigned appointments:


Associated with this sort of query (in the sense of exploring the past) are filters that let us search around dissolved companies, for example:


(I should probably also put some time filters in there, for example to search for companies that a particular person was a director of at a particular time…)

We can also search into the disqualified directors register. To try to reduce the sense of turning this into a fishing trip, searching by director name and then filtering by locality feels like it could be handy (though again, this needs some refinement on the way I apply the locality filter.)


Next step on this particular task is to tidy these up a little bit more and then pop them into a Slack responder.

But there are also some other Companies House goodies to come…such as revisiting the notion of co-director based company maps.


Author: Tony Hirst

I'm a Senior Lecturer at The Open University, with an interest in #opendata policy and practice, as well as general web tinkering...

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