Find or recover your Government Gateway user ID and password

By Max Szolcek, founder of Dormant Return. Last updated 17 September 2026

A Company Tax Return is filed under the company's own Government Gateway sign-in, and for a dormant company that sign-in may not have been used since the last return, a year ago. This guide is for the moment you sit down to file and cannot find the user ID, cannot remember the password, or are not sure the account you have is the right one. It covers where the details are written down, how HMRC's recovery works, what to do when the account was set up by someone who has moved on, and who to contact when the self-service routes run out.

Which sign-in a CT600 needs

HMRC's sign-in page offers two kinds of account. A Government Gateway sign-in is a user ID of up to 12 characters plus a password. A GOV.UK One Login is an email address plus a password. Filing software, this service included, submits a CT600 with a Government Gateway user ID and password: One Login details are refused by the Gateway with error 1046, however correct they are.

The account also has to be the right kind. HMRC accounts are set up for an individual, an organisation or an agent. A company's Corporation Tax is filed from the organisation account that was enrolled for Corporation Tax against the company's UTR, not from a director's personal tax account. If you only have a personal sign-in, you do not yet have what a CT600 needs; skip to creating a sign-in for the company.

Where the user ID is written down

The user ID is not a number you choose, so it is easy to lose and easy to find again once you know where to look.

HMRC's confirmation when the account was created. The user ID is shown on screen at the end of set-up and sent to the email address given at the time. Search that mailbox for "Government Gateway user ID".
Inside the account. If anyone can still sign in, the business tax account's account-details page shows the user ID. Copy it somewhere safe, along with the email address and phone number the account uses for security codes.
Whoever set the company up. A formation agent, the previous director or the company's accountant may hold it. Note the caveat below about accountants: their own agent sign-in is not the company's.
Old filing software or a password manager. The CT600 filed last year went out under the same user ID; whatever filed it may still have the credentials saved.

Forgotten user ID, forgotten password

gov.uk keeps this short: "You can recover or reset your sign in details if you've lost them. You'll be told how to do this when you try to sign in." In practice the sign-in page offers one route for a lost user ID and another for a lost password, and both rely on the contact details registered on the account, so they are quick when you still have access to that email address or phone, and slow when you do not.

Lost the user ID: the recovery route sends it to the email address on the account. You will need to know that address, and it has to still be one you can read.
Lost the password: the reset route needs the user ID, then proves it is you through the account's email address or phone number before letting you set a new one.
Lost both: recover the user ID first, then reset the password.

Two things to avoid. First, guessing the password repeatedly: gov.uk says an account that is locked "will unlock after 2 hours" and that "Helpdesk advisers cannot unlock your account", so a run of wrong guesses costs you the afternoon. Check the details work by signing in at gov.uk before filing anywhere. Second, giving up on the account and creating a new one: a fresh Government Gateway account has no Corporation Tax enrolment, so it cannot file until it has been enrolled and activated with a code that arrives by post. Recovering the old account is almost always faster.

The account belonged to a former director or accountant

This is the common hard case. An accountant files through their own agent account, authorised against the company's UTR; that authorisation never gave the company a sign-in of its own. And an account created by a director who has since left is registered to their email address and phone, so the recovery routes go to them, not to you.

If nobody who can still sign in is willing to help, the way forward is to create new sign-in details for the organisation ("Create new sign in details" on HMRC's sign-in page), then add Corporation Tax to the new account and activate it with the code HMRC posts to the registered office. The steps, what you need, and the wait for the code are in enrol for Corporation Tax online before you file. Start straight away if a filing deadline is near: the postal code is the slow part.

The sign-in works but filing still says 1046

Error 1046 is the same message for a wrong password, a One Login sign-in used where a Gateway one was needed, a Gateway account with no active Corporation Tax enrolment for this company, and a return carrying a different UTR from the one the account is set up for. If the user ID and password sign you in at gov.uk, two checks remain, both in the business tax account:

The UTR. Open Corporation Tax and compare the UTR shown there, digit by digit, with the one on the return. A personal Self Assessment UTR or another company's UTR looks just like the right one, and it is an easy mistake to make. Company UTR vs personal UTR explains how to tell them apart. On Dormant Return you can change the UTR on the filing page after a refused sign-in, without paying again.
The enrolment. If Corporation Tax does not appear at all, or shows as awaiting activation, add and activate it before trying again. If you signed in as a team member rather than the administrator, the administrator has to give you access to Corporation Tax.

The full list of what HMRC's error codes mean is in CT600 rejected by HMRC: what the error codes mean.

Who to contact at HMRC

HMRC's online services helpdesk deals with sign-in problems, error messages in online services and trouble receiving access codes. At the time of writing the number is 0300 200 3600 (from outside the UK, +44 161 930 8445), Monday to Friday, 8am to 6pm, closed on bank holidays; Relay UK is available by dialling 18001 first. HMRC also offers a digital assistant online, with a hand-off to webchat with an adviser when one is available. Check gov.uk for the current details before calling, and remember that advisers cannot unlock a locked account.

With Dormant Return, a return you have paid for waits while you sort the sign-in out. A refused sign-in leaves the return paid and ready; we email you a link back to it after half an hour, and if it is still unfiled 24 hours after payment we close it and refund the fee automatically, so nothing is lost by taking the time to recover the right account. Please do not pay for a second copy of the same return in the meantime: the first one is waiting.

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