If you’re using CalCal and this is the first time you’re sending your tax return online, there are a few steps you need to follow.
You can sign up with CalCal and start filling out your tax return in the meantime, but before you can submit, you need to:
- Register:
Visit the HMRC website to “register and file your self-assessment tax return” - Get your UTR number:
You’ll set up HMRC sign-in details and then you’ll be sent your 10-digit Unique Taxpayer Reference (UTR) number in the post if you don’t already have one. Create or recover sign-in at Log in or register for HMRC online services. - Get your activation code:
This will also be sent by post, and will allow you to file online. The code can take up to seven days to arrive, so you need to make sure you register well in advance of the 31st January deadline. - Activate your account:
Activate your online HMRC account within 28 days. Otherwise, the code will expire and you’ll need to request another one.
Submitting through CalCal (Government Gateway)
When you use Check and Send in CalCal, you sign in with a Government Gateway user ID (up to 12 characters) and password.
- This is Government Gateway — not GOV.UK Verify (Verify is closed), and not your GOV.UK One Login email sign-in.
- If you already use Government Gateway for HMRC Self Assessment, use those same details in CalCal.
- If you only use GOV.UK One Login for HMRC, create a unique Government Gateway user ID for commercial software. HMRC’s steps: Check how to submit a Self Assessment tax return using commercial software.
Step-by-step in the app: How to find and submit your Self Assessment return in CalCal. Authentication problems: HMRC Authentication failure – Possible Reasons.
Once registered with HMRC, follow How to find and submit your Self Assessment return in CalCal (or the older legacy Self Assessment in CalCal guide). If you are on MTD for Income Tax, see MTD for Self Assessment instead.