Before you can submit anything, you need to connect AccountsPortal to HMRC and complete a short setup. You only do this once.
Go to Settings and select Making Tax Digital in the Integrations section. If you have never connected before, you'll see the "Enrol with HMRC Making Tax Digital" page with a short explanation of MTD.
IMPORTANT: You must already have a Government Gateway account before you start.
Tick "ITSA" (MTD for Income Tax Self Assessment). You can also tick "VAT" at the same time if you want to use MTD for VAT as well. Then click "Integrate with MTD".
(If you have already connected for VAT, you'll see a "Connect MTD for Income Tax" button - clicking it adds Income Tax to your existing connection.)
You'll be taken to the HMRC sign-in page. Sign in with your Government Gateway details and grant AccountsPortal permission to interact with your Income Tax account. HMRC then sends you back to AccountsPortal and you'll see a confirmation that you have enrolled.
Back on the Making Tax Digital page, the "MTD for Income Tax Self Assessment" card will show as "In Progress" with the message "Complete the setup below to finish your Income Tax integration".
Work through the three steps:
1. National Insurance Number - enter your National Insurance Number, then click "Continue". (The Continue button stays disabled until a valid number is entered.)
2. MTD Business - AccountsPortal asks HMRC which businesses are registered against that National Insurance Number and lists them in a dropdown, shown as the trading name followed by the business type, for example "Acme Trading (Self-Employment)". Choose the business you are reporting for and click "Continue".
If nothing is listed, you'll see "No businesses found for this National Insurance Number" - check the number and that you are registered for MTD for Income Tax with HMRC.
3. Confirm - AccountsPortal displays the Business Type that HMRC holds for the selected business. Click "Save MTD Data" to finish.
Once setup is complete, the card changes to "connected" and shows your details:
The "Accounting Period Start" determines the dates of your quarterly updates. There are two options:
- Standard (6 April) — the period starts on 6 April.
- Calendar (1 April) — the period starts on 1 April.
If you have not yet submitted any return, you can change this using the dropdown. Once you have submitted your first quarterly return for the tax year, the Accounting Period is locked and cannot be changed.
Your Share defaults to 100% and most people should leave it there.
Set it lower only if:
Your quarterly figures are reduced to this share automatically. On the report, View Details shows a Full amount column beside Your share so you can see the underlying values.
You can change Your Share at any time, but any changes will only affect reports that have not yet been saved. Reports already submitted keep the share they were filed at and are never altered.