After 3 years of close collaboration between the Government Digital Service (GDS) and HM Revenue and Customs (HMRC), GOV.UK One Login is now being rolled out to new HMRC users. This implementation represents a significant milestone for the cross-government project.

Since February, a proportion of users who access HMRC services online for the first time have been directed to sign in or create sign in details through GOV.UK One Login. This is another significant step towards a simpler, more consistent experience for people accessing government services online.

Over the coming months, we will be rolling this out to more new HMRC users until GOV.UK One Login becomes the standard route for everyone accessing HMRC services for the first time.

My role as the GDS team lead for the HMRC engagement is to ensure the GOV.UK One Login platform enables users’ smooth access to HMRC’s services. That means working closely with our HMRC colleagues to understand what they need, turning those needs into practical work our teams can deliver, and making sure the platform works well for everyone who uses it.

How we got here: building a shared solution

Delivering a cross-government service of this scale required deep, collaborative work including:

• Framing the challenge: We started by gaining a clear picture of just how complex the project would be as HMRC services are among the largest and most-used digital services in government.
• HMRC and GDS integration: The teams from GDS and HMRC partnered to understand exactly what HMRC needed, covering everything from day-to-day running of their services to the essential work of keeping our combined systems safe and reliable for everyone.
• Building together: We built solutions together that work across both organisations, so that users get a seamless experience.
• Testing and iteration: Rigorous testing was essential. We used user feedback to iterate on page language and layout, resolving specific points of confusion identified by users.

Go live: the moment the button was pressed

The go live day for this milestone (9 February 2026) was worth celebrating. A small group of the core GDS team travelled to HMRC offices to be there in person when we switched the service on.

The joint GDS-HMRC team is spread right across the UK, making this in-person gathering a momentous occasion. Crucially, the launch went smoothly, and we celebrated the first successful users accessing HMRC services via GOV.UK One Login, complete with celebratory cake.

The next phase: monitoring and iterating

Going live was just the beginning. We have established joint reporting measures and are now actively monitoring metrics to ensure the service continues to run smoothly and provides a positive user experience. We are tracking the:

• number of people using GOV.UK One Login to access HMRC services
• success rate and potential areas of ‘friction’ for users proving their identity via GOV.UK One Login
• contact centre call volumes related to the new service

We will use this data to ensure we continue to meet user needs and that people can complete their required interactions with HMRC easily and effectively.

What’s next

Reaching this point has taken a huge amount of work from both teams. However, there is more to come. Our next priority is bringing existing HMRC users onto GOV.UK One Login. These are users who already have and actively use Government Gateway to access HMRC services.

We are continuing to work closely with our HMRC colleagues to take forward this essential next phase of work. Ultimately, the goal is the same as it has always been: making it simpler and easier for people to access the government services they need online.

P.S. The cake was delicious – I could have had a second slice, and I am very particular about cake.