GOV.UK One Login is the government's single sign-in for its online services. You sign in with an email address, a password and a security code sent by UK text message or an authenticator app. It works with some services today, not all, and GOV.UK says it'll eventually replace every other way to sign in, including Government Gateway.
That last part is why so many people end up confused. Right now you might use One Login for one service and a Government Gateway user ID for another, sometimes both for HMRC. Both are official, and which one you need depends on the service and what you've used before.
Below: how One Login works, when to use it instead of Gateway, how security codes work, and the fixes for the problems people hit most.
What GOV.UK One Login does
One Login lets you use the same sign-in details across government services that have joined it. Once you're in, you can:
- change your sign-in details, including your email, password or how you get security codes,
- see the services you've used with your One Login,
- delete your One Login.
You don't create it in advance. If a service needs One Login and you haven't got one, you create it the first time you use that service. GOV.UK says it doesn't work with every service yet, giving Universal Credit as an example of one that still uses its own account.
One Login or Government Gateway?
For HMRC, GOV.UK gives clear rules:
| Your situation | Which sign-in to use |
|---|---|
| You already use HMRC online services with a Gateway user ID | Keep using your Government Gateway user ID, even if you have One Login for something else |
| You already use One Login for HMRC personal tax services | Keep using One Login |
| You've never used HMRC online services | Choose Create new sign in details, and HMRC guides you to Gateway or One Login |
Government Gateway signs you in with a user ID of up to 12 characters. One Login uses your email address. If you're not sure which you set up, look for a 12-character user ID in old HMRC emails or letters. If you mostly deal with HMRC on your phone, see our guide to the HMRC app.
How security codes work
When you create your One Login, GOV.UK sends you a code by email to confirm the address. After that you choose how you'll get codes when you sign in:
- a text message to a UK phone number, or
- an authenticator app on your phone, tablet or computer.
Codes expire after 15 minutes, and if you ask for several, only the most recent one works. Here's the catch people miss: GOV.UK can't text codes to a phone number registered outside the UK. If you live abroad or use a non-UK number, you'll need an authenticator app or a UK mobile, and if you set up a non-UK number before, you'll be asked to switch next time you sign in. Picking an app is covered in the best authenticator apps.
When your security code doesn't arrive
- Select send the code again.
- Check your phone has signal and that you haven't blocked the sender.
- For email codes, check spam or junk, and if it's a work address ask your IT team whether emails from GOV.UK One Login are being blocked.
- Make sure you're typing the newest code, and that it's under 15 minutes old.
- If you've lost your phone, use your backup method if you added one, such as a second UK number or an authenticator app.
If you've lost every method, you may be asked to prove your identity again before you can change how you get codes.
For company filings, my guide to the Companies House login shows how WebFiling and shared logins fit in.
Proving your identity with One Login
Some services also ask you to prove who you are. The GOV.UK One Login app has now replaced the older GOV.UK ID Check app for most people, while the ID Check app is mainly for some HMRC services accessed with Government Gateway. You'll need a phone with a camera, and the accepted photo ID includes a UK photocard driving licence, a UK passport or a non-UK passport with a biometric chip.
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Two details that save a wasted attempt: you can't use an expired passport, but a DVLA driving licence that expired within the last 90 days is accepted. And you should always start on the service you're trying to use, not by downloading the app on its own.
If you live outside the UK
Expats and overseas business owners trip up here more than anyone. You can still use One Login from abroad, but you can't get security codes by text to a non-UK number. Set up an authenticator app when you create your One Login, or before you next sign in if you previously used a non-UK number. If you can't manage it alone, GOV.UK says you can ask someone you trust to help, and you can contact the GOV.UK One Login team to report a problem.
HMRC online still has its own sign-in, so see my guide to the Government Gateway account for that side.
What's coming next
The One Login roadmap, last updated in August 2026, lists work on proving identity with open banking, using information held by DWP to answer security questions, a digital driving licence in the app, and letting people delete and recreate their One Login if they lose access to their two-factor methods. Passkeys are already live, so you can sign in with your fingerprint or face instead of a password.
My advice if you run a small business: set up an authenticator app as a backup today. It's the one step that stops a lost phone turning into a week locked out of your tax account.
Frequently asked questions
What is GOV.UK One Login?
It's the government's single sign-in for online services, using an email address, password and a security code. It works with some services now and will eventually replace Government Gateway.
Should I use One Login or Government Gateway for HMRC?
If you already use HMRC with a Gateway user ID, keep using it. If you've never used HMRC online, choose Create new sign in details and follow the guidance.
Why can't I get a GOV.UK One Login code by text?
Codes can only be texted to UK phone numbers. With a non-UK number, use an authenticator app or a UK mobile instead.
How long does a One Login security code last?
It expires after 15 minutes. If you requested more than one, only the most recent code works.
Can I use passkeys with GOV.UK One Login?
Yes. Passkeys are live, so you can sign in with your fingerprint or face scan instead of a password.
