SelfSubmit is designed to help you stay compliant with HMRC Making Tax Digital requirements. You remain responsible for ensuring the information you submit is accurate.

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How tax due works

Overview of quarterly updates, the final declaration, and where HMRC displays tax due and payment dates.

Last updated: 20 July 2026

1. The MTD reporting cycle

  1. During the tax year — quarterly updates
    You submit digital summaries of business income and expenses to HMRC (from SelfSubmit records when filing is enabled). These update HMRC during the year. They are not normally a full annual tax liability for each quarter.
  2. Year end — final declaration
    You confirm the full year’s figures (comparable to completing Self Assessment). HMRC then produces a tax calculation from the information submitted and other data held (for example PAYE).
  3. Payment
    Pay the amounts shown in your HMRC account by the stated due dates. Many taxpayers also make payments on account (commonly 31 January and 31 July) under Self Assessment rules.

2. Where tax due is shown

  • HMRC online (primary source) — Your Personal Tax Account / Self Assessment service shows the tax calculation, balance, and payment dates. Access via GOV.UK HMRC online services.
  • HMRC correspondence — You may receive online messages or postal notices. Treat the online tax calculation as authoritative.
  • SelfSubmit — Use SelfSubmit for digital records, receipts, deadlines, and MTD update submissions. The tax calculator provides an indicative estimate only and is not HMRC’s official liability.

3. SelfSubmit scope

Included: recording income and expenses, storing receipts, tracking obligations, and submitting MTD in-year quarterly updates for self-employment when your HMRC connection and product settings allow.

Not included yet: submitting a Final Declaration from SelfSubmit, UK property / foreign property MTD API filing, or replacing HMRC’s official tax calculation or payment interface. For Final Declaration and other MTD-compatible products, see GOV.UK — find MTD-compatible software. The amount payable remains the figure shown in your HMRC Personal Tax Account.

4. Recommended practice

  • Maintain monthly records in SelfSubmit so quarterly totals are available when due.
  • After the final declaration, review the tax calculation in your HMRC account before paying.
  • Diary both submission deadlines and typical payment dates (January / July where applicable).
  • If figures appear incorrect, correct your records and contact HMRC or a qualified accountant. Do not leave discrepancies unresolved.

5. Disclaimer

Tax rules change. This page is general information, not personal tax advice. You remain responsible for accurate figures and timely payments. See our Disclaimer and confirm current rules on GOV.UK.