Mandation for Making Tax Digital (MTD) for Income Tax and Self Assessment (ITSA) started on April 6th 2026 for sole traders and landlords with a turnover exceeding £50,000.

As an Affinity user, you will be able to file quarterly updates and manage other income sources on behalf of your customer. To do this you will need:

• An Agent Services Account (ASA) connected to your Affinity account.
• One or more sole trader or landlord managed profile.
• An Agent Filing link (explained further down).

Pricing

MTD for ITSA is automatically included for all L and XL profiles at no additional cost. An additional annual subscription may be required for smaller profiles or Affinity accounts under a certain monthly spend.

Affinity MTD ITSA pricing →

HMRC Enrollment

Before you access the MTD ITSA functionality in QuickFile the managed business must first be enrolled on the MTD ITSA programme with HMRC. Please use the following link to find out more about enrollment and to start the process:

• MTD ITSA enrollment for Tax Agents

QuickFile reporting categories

For a given tax payer (NINO) HMRC have three distinct reporting categories, generally speaking a quarterly update is required for each category:

• Self employment business activity - One update per registered self employment
• UK property income - One update covering all properties
• Foreign property income - One update per foreign property / jurisdiction

QuickFile uses mapping rules to map specifc nominal codes to HMRC cumulative update types and income / expense lines. It is recommended that you take a look at the MTD Account Configurator to understand if more complex activity for a given individual will need to be distributed across multiple QuickFile accounts.

Configure an Agent Filing link

Once you have connected your HMRC Agent Services Account to QuickFile Affinity, you will need to create an Agent Filing Link in order to access and update a customer’s self-assessment information. A new Agent Filing Link can be created from the profile detail screen for the business you want to connect to.

For self-assessment connections, you will need to provide the name and National Insurance Number corresponding to the individual’s tax account.

Once the Agent Filing link has been established the customer’s Tax account will be visible in the HMRC Connect screen when logged into their account.

What’s next?

Now your client is on the MTD ITSA programme and you have access to their self-assessment account, a good place to start exploring the self-assessment functionality in QuickFile is the Workflow page, this is the hub for all things self-assessment and allows you to reach all the different areas for reviewing and completing your customer’s self-assessment obligations.

Click here to read more about the self-assessment Workflow area

You can file a cumulative update to HMRC whenever you like, although as a minimum an update must be sent once per quarter.

Click here to read more about Cumulative Updates

Note: Making Tax Digital for Income Tax and Self Assessment is still in it’s infancy. We encourage you to contact us about any issues or recommendations you may have.