Tax Calculations

What this is

The Tax Calculations page lets you see HMRC’s calculated tax position based on the data you have submitted. There are two modes: an in-year Tax Estimate that gives you a running estimate of your tax liability, and an Intent to Finalise calculation used as part of year-end.

What you see on screen

The calculations page at /app/calculations shows:

Calculation mode selector - switch between “Tax Estimate” (in-year) and “Tax Calculations” (intent to finalise)
Current calculation - the latest tax calculation from HMRC showing your estimated tax liability
Calculation history - a list of previous calculations you have triggered
Detail panel - click any calculation to see a full breakdown of income, allowances, and tax due

Tax Estimate (in-year)

The in-year estimate gives you a running view of your tax position based on quarterly data submitted so far. This helps you plan for your tax bill throughout the year.

Tax Calculations (intent to finalise)

This mode shows the calculation HMRC produces when you are preparing for your Final Declaration at year end. It includes all submitted data and is the basis for your final tax liability.

How to use

Navigate to Tax Estimate or Tax Calculations in the sidebar
Click Estimate My Tax or Calculate to trigger a new calculation from HMRC
Review the result showing your estimated income tax and National Insurance
Click on any calculation in the history list to see the full breakdown

Things to know

Calculations are generated by HMRC. Aligned requests the calculation from HMRC’s systems - the figures come directly from HMRC based on your submitted data.
The estimate updates as you submit more data. Each time you file a quarterly update, you can trigger a new estimate to see your updated tax position.
This is not a final tax bill. The in-year estimate is indicative. Your actual tax liability is determined at year end through the Final Declaration process.

Several related screens provide additional tax data:

BSAS (/app/bsas) - Business Source Adjustable Summaries showing cumulative income and expense totals with any accounting adjustments
Annual Allowances (/app/annual-allowances) - capital allowances and annual adjustments for your income sources
Other Income (/app/other-income) - income sources outside your quarterly business updates (dividends, savings, employment)
Losses (/app/losses) - brought-forward losses and current-year loss claims

These pages complement the main tax calculation by showing the detailed components that feed into it.