HMRC’s Third Party Developer Conference

It’s been a busy week or so for HMRC Digital. On 1 September Mark Dearnley and I were in Telford for the official opening of our latest Digital Delivery Centre. We’ve set it up with Capgemini who will also be able to use it with other clients. The Financial Secretary to the Treasury, David Gauke MP was there to cut the ribbon and see first-hand how we are continuing to build our digital capability.

I was also delighted to host last week’s developer conference at the Royal Society to discuss HMRC's API strategy with 100 developer colleagues. It was a high energy day with presentations from Jim Harra the Director General for Business Tax and Mark Dearnley, HMRC’s CDIO.

Jim set the business context and outlined our vision for Making Tax Easier. Mark shared the vision for APIs and our API first approach. And, he emphasised how we want to work with the industry to build high quality tax products for our joint customers.

We broke into a series of discussion groups and delegates had the opportunity to debate and question tax experts on Making Tax Easier exploring their early thinking.

We were absolutely privileged to host our minister again, who delivered the keynote speech and told delegates “This is a chance to help deliver the tax services of tomorrow, and transform the way millions of people interact with HMRC”.

We ran a second series of discussion groups debating the API strategy in more detail, gave delegates a glimpse of the Developer Hub - illustrating the private beta due in November - and some insight into how we developed the Multi-Channel Digital Tax Platform.

There was a huge amount of debate during the day, with delegates telling us what was important to them, this included;

  • lively debate on webhooks and other callback mechanisms
  • how we will separate tokens in the sandbox environment from production
  • moving from XML to JSON and what that might mean
  • the next level of detail; delegates wanted more, more, more…

Watch this space over the next few weeks. We have given a commitment to come back in four weeks with our roadmap to convert existing APIs to JSON alternatives and the timetable for publishing the new digital APIs developed to support services such as the Business and Personal Tax Accounts.

Brigid and her team have some innovative ideas for gathering feedback on developer priorities to inform the roadmap – I can’t wait to see what they have in mind.

Please get involved – leave us a post and share your thinking with the community – or, you can email our support team at

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  1. Comment by Mike Potter posted on

    Thanks for the links. Interesting article. For info, we follow guidance set out by the Government Equalities Office as well as the Government Digital Service

  2. Comment by Mx Margaret D. Jones posted on

    Almost on topic, and certainly of interest: an advice to web development teams everywhere, concerning titles in online and hardcopy forms.

    I'm one of the earliest users of the non-binary transgender title Mx or Mix, and I have written by far the longest and most comprehensive article about it (November 15, 2015). The article has a lot of information about the use of titles etc in form design.

    It would be great to correspond with form makers about how you might improve your online or hardcopy forms. The article is 20,000 words, nearly 50 pages including appendices:

    Anchor link to 'Form makers and designers'

    Appendix Four:

    --Mix Margaret D. Jones
    +61 414374701
    Perth, Western Australia

  3. Comment by Brigid McBride posted on

    Thank you for your suggestion and we will be looking at all aspects of the Corporation Tax API after we have done the work on the first APIs announced in Bridget's blog, we will of course keep the community updated as we go along

  4. Comment by Brigid McBride posted on


    Thanks for your feedback and yes we do need to take the ideas of the community on board, we only achieve our joint objectives if we work together. We can’t do everything at once but I hope you are seeing progress with the publication of our API roadmap

  5. Comment by Brigid McBride posted on

    Kevin thank you for your comments, I am glad you were able to raise the concerns over excessive burdens with me on the day of the Software developers conference. We are working through all comments raised on the day and others that were raised in different forums, as we go forward in our journey we will be sharing our thinking with the community, including how we minimise disruption to developers, from modernising services

  6. Comment by Kevin Wright posted on

    Hi Brigid,

    As I mentioned to you on the day, there are international trade declarations like ICS and EMCS where the same XML schema is used throughout all EU member states. It seems to be an excessive burden to require software developers to have to develop completely different messages for the UK as we have to for everywhere else.

  7. Comment by Arun posted on

    Hi Mike,

    I like the HMRC's initiative in collaborating with Software Developers right from start and discussing ideas from our companies perspective what is important, I appreciate it and as much as the ideas we received from you it will be great if HMRC takes it serious to accept our suggestions as well.

  8. Comment by ali posted on

    Is it necessary for business to submit tax conputations at all with their accounts?

    The purpose of XBRL is to provide a computer processable standard format of exchanging accounting data.

    Tax computations are perfomed on the data contained in the XBRL accounts in accordance with the rules established by the HMRC.

    So, all the HMRC needs is XBRL accounts, and their own internal software to work out the tax to be paid by a business.


    1. Company sends XBRL accounts to HMRC
    2. HMRCS internal software performs Tax Computation using the XBRL data
    3. HMRC sends Company Tax Demand with Detailed Report on how the tax computations was worked out.

    In this case the Company Software will only need to prepair their accounts and send them to HRMC, and all the complexcity of the ever-changing taxation rules will be on the HMRC side.

  9. Comment by Brigid McBride posted on

    Sylwester - Thank you for your question, this is an option which we are looking into with colleagues in the Cabinet office, a great question.

  10. Comment by Brigid McBride posted on

    Paul - Thank you for your comments, agree a shared understanding of the schema definitions is key , however we do want to modernise to allow us to move to a space where we jointly deliver services that are attuned to user needs that not only are capable of transmitting data at an enterprise level but allow us to deliver great services quickly according to rapidly evolving customer needs. We want to do this across all our taxes, and dare I say blurring the distinctions where necessary, delivering wherever possible a single view. We believe a modern platform will help us to achieve that primarily using JSON - but it's a great talking point - would be good to hear others views. please keep them coming in; as always we aim to provide services for our customers and your feedback is valued.

  11. Comment by Steve Checkley posted on

    Hi Mike,

    Thanks for inviting us and many other developers to the conference. It was a very informative day.

    I look forward to seeing how this strategy develops.

    Kind regards,


  12. Comment by Paul Nicklin posted on

    "moving from XML to JSON and what that might mean"
    The mess that the new co house api is in... only 10 times worse because of the message complexity.

    We need strong schema definitions for the very large, complex messages involved. By all means provide a JSON API for the scripting folk, but piggy back it onto a well defined XML one for those of use writing proper enterprise grade stuff.

  13. Comment by Sylwester Cabaj posted on

    Do you think it would be a good idea to apply for the ISO27001 to assure the public that the data is safe?