Self Assessment Login HMRC Guide to Gateway and One Login
Signing in to Self Assessment starts on one GOV.UK page, but HMRC now offers two routes through it. Returning filers mostly use a Government Gateway user ID. Many people new to HMRC online use One Login instead. Pick the right route and most login trouble disappears before it starts.
Two Ways Into Your HMRC Account
Every HMRC sign in now runs through either Government Gateway or GOV.UK One Login. Both open the same Self Assessment service once you are through.
Government Gateway
Government Gateway is the older route. You sign in with a user ID of up to 12 characters and a password. HMRC then sends an access code by text, voice call or authenticator app.
GOV.UK One Login
One Login uses your email address as the username. HMRC opened it to new customers on 9 February 2026. The same login works across more than 200 government services, so you may already have one.
Which Sign In Route Fits Your Situation
Your route depends on your history with HMRC, not on personal choice. Find the description that matches you.
You Have Filed Online Before
Keep using your Government Gateway user ID. This holds even if you later set up a One Login for another government service. HMRC expects to move existing users to One Login between late 2026 and 2027.
You Are Filing for the First Time
HMRC now points new individual taxpayers towards One Login. On the sign in page, choose Create new sign in details and follow where HMRC sends you. You also need to register for Self Assessment, which gives you a 10 digit Unique Taxpayer Reference (UTR).
You Work for Yourself
Sole traders and self employed people still use Government Gateway, even when they are new. HMRC does not class them as individuals for the One Login rollout. Write your user ID down the moment it appears on screen. Our accountants for freelancers can set this up with you on your first return.
Someone Else Files for You
Your accountant should never sign in with your details. Agents use their own HMRC agent account once you authorise them. If an accountant once filed using your own login, you may need a fresh Gateway user ID to file yourself later.
Getting Into Your Account Step by Step
Type the address yourself rather than clicking a search advert. Copycat sites often sit at the top of search results.
Open the HMRC online services sign in page on GOV.UK.
Select Sign in.
Choose Government Gateway or GOV.UK One Login.
Enter your user ID or email address and your password.
Type the access code HMRC sends you.
Open Self Assessment from your personal or business tax account.
A first sign in can also ask you to confirm your identity. Some services use the GOV.UK ID Check app, which reads your photo ID. Keep your passport or driving licence in date so the check works first time.
When Your HMRC Login Will Not Work
Each error has a usual cause. Read the heading that matches your screen.
“HMRC Does Not Recognise My Details”
You may be trying the wrong route. Someone who filed through Gateway for years will not find their records under a new One Login. Search your inbox for old HMRC emails to see which details you used. A typo in a long user ID causes the same message.
“I Cannot Remember My User ID or Password”
Begin signing in and select the recovery option for the detail you lost. HMRC may ask for your National Insurance number or UTR to confirm it is you. Recovering the old details beats creating a new account, which would have no tax records attached.
“I Have a New Phone Number”
Sign in with your user ID and password as normal. At the access code screen, choose the help option and update where codes go. If you no longer have the old phone at all, the online services helpdesk can step in.
“HMRC Has Locked Me Out”
GOV.UK says five wrong attempts lock your account for two hours. Nobody at HMRC can lift the lock early, so calling will not speed it up. Use the wait to find your correct details, then try once more.
“Self Assessment Is Missing From My Account”
Your sign in works, but the service is not attached yet. Choose to add a tax, enter your UTR, and wait for HMRC’s activation code by post. That code can take up to 10 days, and you can request a fresh one if it expires.
“My Software Rejects My Login”
Tax software only connects through Government Gateway details. One Login users must create a separate Gateway user ID for it. Open Profile and settings in your personal tax account, select Manage next to Sign in details, and set it up there. Our cloud accounting team can link your software to HMRC for you.
Before You Ring HMRC
Many login problems clear without a phone call. If yours does not, ring the right line first time.
Line | Best for | UK number | From abroad |
|---|---|---|---|
Online services helpdesk | Sign in, access codes and error messages | 0300 200 3600 | +44 161 930 8445 |
Self Assessment general enquiries | Returns, payments and UTR questions | 0300 200 3310 | +44 161 931 9070 |
Both lines open Monday to Friday, 8am to 6pm, and close on bank holidays. Have your UTR and National Insurance number beside you, as advisers ask security questions first. Relay UK users can dial 18001 before either number. HMRC’s digital assistant can also pass you to a webchat adviser when one is free.
Paying Your Tax Bill Without Logging In
A broken login does not block payment. Paying on time keeps interest down, even if your return follows later.
Send a bank transfer using HMRC’s account details from GOV.UK, quoting your UTR.
Take an HMRC paying in slip to your bank and add a K after your UTR.
Post a cheque made out to “HM Revenue and Customs only” to HMRC, Direct, BX5 5BD, with your UTR.
A Login Plan for the Weeks Before 31 January
Most login stress lands in the final fortnight. A simple plan spreads the work out, and tidy bookkeeping through the year makes the return itself far quicker.
Late November. Sign in once and confirm your user ID, password and access codes all work.
Early December. Add Self Assessment if it is missing, so the activation code arrives in time.
Mid December. Add an authenticator app as a backup to text codes.
Early January. Start your return and save screenshots of any error pages.
31 January. File by midnight to avoid the automatic £100 late filing penalty.
If a lockout or outage stops you on deadline day, keep your screenshots and call records. HMRC can cancel a late filing penalty when you had a reasonable excuse. You still need to file as soon as the problem clears. If HMRC later opens an enquiry into your return, our tax investigation services can represent you.
Keeping Your HMRC Login Safe
Fraudsters copy HMRC branding to steal sign in details. HMRC never texts or emails a link asking for your password. Treat any message offering a tax refund through a link as fake.
Bookmark the HMRC online services sign in page and use only that link. If something looks wrong, the GOV.UK sign in help page lists the official fixes. Store your user ID and password in a password manager too.
Getting Help From a Self Assessment Accountant in Leeds
Some people would rather hand the whole job over. SAS Yorkshire works with sole traders, landlords and directors across Leeds, Batley and the wider Kirklees area. As your agent, we file through our own HMRC agent account, so you never share your password.
Our self assessment tax return accountant team prepares your return, checks your expenses and submits it to HMRC. For planning beyond a single return, our tax advisor leeds service looks at the year ahead. You can contact us to book a call well before the January rush.
Your Questions Answered
Can I have both a Government Gateway ID and a One Login?
Yes, and many people do. Your Self Assessment records stay with the route you used to set them up. Sign in with that one until HMRC moves you across.
Can I check my Self Assessment on my phone?
Yes. The HMRC app opens the same account using the same sign in details. It suits quick checks, while a computer is easier for filing a full return.
Can I file on paper instead?
The paper deadline for the 2025 to 2026 return was 31 October 2026. A paper return sent now counts as late. Online filing by 31 January is the only on-time route left.
Why does HMRC keep asking for an access code?
The code is a second check that the person signing in is really you. It protects your tax records even if someone learns your password. An authenticator app gives you codes without waiting for a text.
