HMRC Introduces GOV.UK One Login Option – What This Means for Accountants
HMRC has begun rolling out a new sign-in experience as part of its long-term plan to modernise how taxpayers and agents access digital services. From 10 November 2025, users signing into HMRC online services may have noticed a new login page that now includes the option to sign in using GOV.UK One Login.
But despite the new visual appearance, nothing changes yet in terms of how you or your clients access HMRC services.
What’s Changing?
HMRC has added a GOV.UK One Login button to the sign-in page. This is part of the government’s wider plan to replace multiple legacy login systems with one unified, secure authentication platform.
However:
- Users must continue to log in using their Government Gateway ID and password
- GOV.UK One Login cannot be used to sign into HMRC yet
- Anyone who clicks the One Login button will simply be redirected back to Government Gateway
- Even users who already have a GOV.UK One Login for other government services cannot use it for HMRC at this stage
This is purely a visual, preparatory update.
Using Capium as a third-party software
From 19 November 2025, users authenticating through 3rd-party software will also see the new sign-in page during OAuth authorisation.
Again, there is no change to how access is granted:
- Keep using Government Gateway ID (10–12 characters) and password
- OAuth flow remains the same
- No technical changes required from developers
- Capium integrations continue to function exactly as usual
What Should You Tell Clients?
Advise clients to:
- Continue using Government Gateway
- Ignore the GOV.UK One Login button for now
- Avoid creating a new One Login account specifically for HMRC (it won’t work yet)
More information is available here:
https://www.gov.uk/guidance/accessing-hmrc-online-services-using-govuk-one-login
To Sum It Up:
This update is part of the government’s gradual shift toward a unified login system, but for now:
✔ No action required
✔ No change to access or workflow
✔ No change to Capium authorisations
✔ Simply continue using Government Gateway
As HMRC moves closer to fully adopting GOV.UK One Login, we’ll keep Capium users updated every step of the way.
