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Tax codes, letters & HMRC login

Government Gateway and HMRC sign-in, explained

To file a Self Assessment return, check your tax code or see what you owe, you sign in to HMRC's online services. There are now two ways to do that — Government Gateway and GOV.UK One Login — plus the HMRC app. This guide explains how they fit together. TaxGo isn't part of HMRC: to sign in, always go to GOV.UK directly.

TaxGo Editorial TeamLast reviewed · Tax year 2025/263 min read
Contents
  1. 01What Government Gateway is
  2. 02GOV.UK One Login
  3. 03The HMRC app
  4. 04Lost your user ID or password?
  5. 05Staying safe
  6. 06How TaxGo fits in

Key takeaways

  • Government Gateway uses a user ID (up to 12 characters) and password.
  • GOV.UK One Login uses your email address and a password.
  • If you already have sign-in details, keep using them. New users are guided to create one or the other.
  • Only sign in via GOV.UK or the official HMRC app. HMRC won't email or text you a sign-in link.

What Government Gateway is

Government Gateway is the long-standing sign-in system for HMRC's online services. You sign in with a user ID of up to 12 characters and a password, usually with a code sent to your phone or an authenticator app as a second step.

Behind the sign-in sit services like your Personal Tax Account, your Self Assessment online account and your business tax account. Your UTR and your Government Gateway user ID are different things — see what a UTR is.

GOV.UK One Login

GOV.UK One Login is the government's newer sign-in, using your email address and a password. HMRC services now accept either. GOV.UK's guidance is simple: if you already have Government Gateway or One Login details, carry on using them. If you're new, select 'Create new sign in details' when you access an HMRC service and you'll be guided through setting one up.

The government is gradually moving more services to One Login, so you may be asked to set it up at some point. When that happens, follow the on-screen steps on GOV.UK.

The HMRC app

The free HMRC app lets you check your tax code, see your National Insurance record, find your UTR and make payments. Once set up, you can sign in with your phone's fingerprint or face recognition, which is often easier than remembering a user ID.

Lost your user ID or password?

  • On the GOV.UK sign-in page, use the option for forgotten sign-in details — you'll usually need access to the email address or phone number linked to your account.
  • If you can't recover it, you may be able to create new sign-in details and then reconnect them to your tax records by answering identity questions.
  • Already set up the HMRC app? You may still be able to sign in there and find what you need, such as your UTR.
  • If none of that works, use the help and contact options on GOV.UK. Have your National Insurance number to hand.

Deadline close?

Sorting out sign-in can take time if HMRC needs to post you a code. If 31 January is near, don't leave it — and keep preparing your return in the meantime so it's ready to submit.

Staying safe

  • Type gov.uk into your browser yourself, or use the official HMRC app. Don't follow sign-in links in emails or texts.
  • HMRC will never ask for your password or bank details by email, text or phone call out of the blue.
  • Never share your Government Gateway user ID or password with anyone, including tax software. A legitimate service never needs your HMRC password.
  • Report suspicious messages using the phishing reporting details on GOV.UK.

How TaxGo fits in

TaxGo is independent software — not HMRC, and not affiliated with it. You don't give TaxGo your HMRC sign-in details. You upload your tax documents, TaxGo prepares your Self Assessment return, and you review and approve it before it's ready for submission.

Questions people ask

Is Government Gateway being replaced?

The government is moving services to GOV.UK One Login over time. For now, HMRC accepts both. If you already have sign-in details, keep using them until you're asked to change.

Is my Government Gateway user ID the same as my UTR?

No. Your user ID is for signing in. Your UTR is your 10-digit Self Assessment reference.

Can I have more than one Government Gateway account?

Many people end up with several. It's simplest to use one set of sign-in details for your personal taxes.

Does TaxGo need my HMRC password?

No. Never share your HMRC sign-in details with any third party.

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Related guides

This guide is general information based on HMRC guidance for the 2025/26 tax year, not personal tax advice. Rules and rates change — check GOV.UK or speak to a qualified adviser about your circumstances.

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