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FeaturesMaking Tax DigitalUpdated March 4, 2026

Tax Liability Estimates

Tax Liability Estimates

From v1.0.285, the platform displays your estimated tax liability after each quarterly submission. This gives you a running view of what you may owe HMRC — updated automatically as you progress through the tax year.

Overview

When HMRC accepts a quarterly submission, their Individual Calculations API (v8.0) generates an updated tax estimate based on all income and expenses submitted so far. The platform retrieves that estimate and presents it in your dashboard so you always know where you stand.

What You Can See

Estimated Tax Due

A running figure showing the total income tax estimated by HMRC based on your cumulative quarterly submissions for the current tax year. This figure updates each time a new quarter is successfully submitted and accepted.

Personal Allowance Utilisation

A breakdown of how much of your personal allowance (currently £12,570 for most taxpayers) has been offset against your cumulative income to date. This helps you understand how much tax-free headroom remains as the year progresses.

Payment-on-Account Implications

An indicative view of your payments on account — the advance tax payments due in January and July. Based on the current HMRC estimate, the platform shows what your payment-on-account obligations could look like, giving you time to plan your cash flow ahead of each deadline.

How It Works

  1. You complete and submit a quarterly update through the platform.
  2. HMRC accepts the submission and triggers a new calculation via the Individual Calculations API (v8.0).
  3. The platform retrieves the updated calculation result from HMRC.
  4. Your tax estimate, personal allowance utilisation, and payment-on-account figures are updated in the dashboard.

This cycle repeats for each of the four quarterly submission windows in the tax year, so your estimate becomes progressively more accurate as more data is submitted.

Supported Income Types

  • Property income (UK furnished and unfurnished lettings)
  • Self-employment income

Both income streams feed into the same unified HMRC calculation, and the estimate shown reflects your combined tax position across all sources.

Important Notes

These are estimates, not final tax bills.

  • Figures are produced by HMRC's own calculation engine via the Individual Calculations API — the platform displays them directly and does not apply its own tax modelling.
  • Estimates may change as subsequent quarterly submissions are made, or if HMRC processes corrections or additional data.
  • The final tax liability is confirmed through your Final Declaration at the end of the tax year.
  • Always consult a qualified tax adviser if you are unsure how your estimate affects your personal tax position.

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