Simple Assessment vs Self Assessment: What's the Difference

Simple Assessment is HMRC's way of calculating tax for certain taxpayers without requiring them to file a full Self Assessment return. Here is how it works.

What Is Simple Assessment?

With Simple Assessment, HMRC calculates your tax based on information they already hold (from your employer, bank, pension provider, etc.) and sends you a calculation showing what you owe. You do not need to file a return.

Who Gets Simple Assessment?

Simple Assessment is typically used for:

• Pensioners whose tax cannot be fully collected through their tax code
• PAYE employees with untaxed income that HMRC already knows about
• People with savings income above the Personal Savings Allowance

Who Does Not Get Simple Assessment?

If you are self-employed, you will almost certainly need to file a full Self Assessment return. HMRC does not have enough information about your business income and expenses to calculate your tax automatically.

Key Differences

| | Simple Assessment | Self Assessment | |--|-------------------|-----------------| | Who calculates tax | HMRC | You (or your software) | | Filing required | No | Yes | | Business income | Not covered | Covered | | Expenses | Not applicable | You claim them | | Deadline | 60 days from letter | 31 January |

If You Are Self-Employed

Simple Assessment does not apply to you. You need Self Assessment — and from April 2026, MTD may apply too. Accounted handles both.

Stop dreading your Self Assessment. Accounted tracks everything throughout the year so January is just a click, not a crisis. Try it free.