Cumulative Updates

What is a Cumulative Update?

A Cumulative Update is a summary of all your income and expenses so far in a given tax year — not just what’s changed since the last time you submitted. Instead of sending only the new information each time, you send the full picture from the start of the period up to now, including any changes or corrections you’ve made along the way.

This makes things a lot simpler. If you’ve had to tweak figures, add late invoices, or fix errors, those get picked up automatically in your next update. It keeps everything tidy and accurate without needing to send separate corrections — which is exactly what HMRC wants as part of Making Tax Digital.

When should I send a Cumulative Update to HMRC?

As a minimum you will need to send a Cumulative Update to HMRC once per quarter. The typical periods would be as follows for the 2026/27 Tax Year.

You can send as many Cumulative Updates as needed, offering flexibility to correct errors, add missing income or expenses, or simply generate a more up-to-date tax calculation.

Checking your Cumulative Update filing obligations

You can view your real-time cumulative update filing obligations from the Workflow page by selecting View Obligations from the Options menu. This page typically displays your four quarterly filing periods, along with their due dates and a status indicating whether each has been received by HMRC.

What information is included in a Cumulative Update?

You’ll need to file a separate Cumulative Update for each of your self-employment businesses, as well as an additional update if you have UK property income. Each update is based on accounting totals for a given period and typically includes your turnover, other income, and categorised expenses such as cost of goods sold, advertising, wages, and staff costs.

For self-employment, you’ll also need to include any disallowable expenses in your cumulative update.

You can find a more detailed breakdown of the cumulative update income and expense categories from the links below.

• Self-employment categories
• UK property categories

Separating your Property and Self-Employment Income

If you have a self-employment business and income from one or more UK properties, you’ll need to submit a separate cumulative update for each business, plus one update covering all your UK property income.

The nominal mapping feature lets you assign specific nominal codes to each income source, enabling you to manage both a self-employment and a property business within a single QuickFile account. However, if you operate multiple self-employment businesses, these must be managed across separate QuickFile accounts.

You can configure nominal mappings in the MTD Settings area by clicking the “Self-employment nominal account mappings” link.

Learn more about nominal mapping configuration →

What happens when all Cumulative Updates have been filed?

At the end of the tax year, once all cumulative updates have been submitted to HMRC, you’ll need to review your records to determine if any final adjustments are required or if additional income needs to be declared. The Self Assessment Workflow page helps you track your progress through this process.

If you need to make accounting adjustments or revise figures from previously submitted updates, you can do so directly from the workflow page.

Once all necessary adjustments and declarations are complete, you can proceed to your Final Declaration. This triggers a tax calculation for the year based on all data submitted to HMRC. You’ll be able to review the calculation, confirm the declaration, and submit it. At this point, your tax year is crystallised, and a payment schedule is generated for any tax due.

File your first Cumulative Update

When you are ready to file your first cumulative update you can review the following guide to help you get started.

Prepare and submit a cumulative update →